Because business majors decided a search engines primary job was actually to serve you ads rather than to help you search for things

It’s largely the first one, at least according to The Man Who Killed Google Search.

See also the Hackernews discussion and this follow-up article by the same author (with links to an article with Google’s response, summaries of other discussions on the topic, etc.)

I could FEEL when amazon removed the not and quote functions... now it's nigh-unusable.

Because search engines are much more complicated than you seem to think. The reason the operators worked back in the day (probably later than 1997 though), was because the search engines actually searched through the contents of the pages they indexed. They used a lot of tricks to make it work, but basically they were matching keywords directly to the index.

Modern search engines are much more complex than that, using a lot more abstraction and interesting techniques to both index and search. The amount of data being indexed has exploded since then, the number of users has exploded and the way people use the internet has changed. To keep costs down and search times low, search engines needed to change drastically. And because most people using search engines won't know how to use those features, they didn't get preserved.

I do wonder what kind of search engines you are talking about though. I assume you mean the big ones like Google and Bing (or sites using those engines) and not like a simple product search on a small webshop. Because as frustrating as using Google and Bing have gotten, they are still amazing tech and not bare-bones at all. The reasons for their failings are only partly in their control and not even really their fault. (Except for the AI thing Google tried, that was 100% their fault and just dumb).

I'm convinced there's an AI in Google search now that reinterprets what you put. It never seems to give me what I search, only what it thinks I mean.

I know at least duckduckgo says on their syntax page that they're aware that operator usage isn't perfect on their site. Seems to come from the fact that they pull results from multiple sources

Guys, please. The solution to Google reinterpreting your search queries has been around for years, and it is called VERBATIM SEARCH. (Search options: All results -> Verbatim). Voila, welcome back to 1997.

I don't know the answer but I can tell you two things:

1. It has often been beneficial to me when the search query wasn't taken literally, it's not always a bad thing. Many searches are ones where the user doesn't know exactly what they're looking for. Granted, that's definitely not always the case. That said, I don't remember ever catching it outright ignore stuff like quoted words/phrases.
2. Regarding "save resources", Google introduced Instant Search in 2010 which started showing results as you type, thus creating an ungodly amount of extra load on their servers since each user search now created multiple queries. They clearly have no trouble scaling up resources.

Have you not had much luck using operators?

I've found them relatively reliable

https://ahrefs.com/blog/google-advanced-search-operators/

https://duckduckgo.com/duckduckgo-help-pages/results/syntax/

https://support.startpage.com/hc/en-us/articles/4521473758228-Advanced-Search-on-Startpage

I'm going to break with what most people are saying and offer the suggestion that search engines are actually doing a decent job. If my mother searches Google for the phrase "Can you please show me a recipe for apple pie?," she's probably going to get a recipe for apple pie. If I search google for "c++20" "std::string" "constructors", after I skip over the ads, I'm most likely going to get a web page that shows me the the constructors for std::string in c++20.

Ad-sponsored pages and AI bullshit aside, most search engines do still give decent results.

The tragedy of the commons.

Enough people don't understand or care to understand, so it gets cut out for the sake of improving the users experience.

It's cheaper for them not to do it and you'll still search so they don't care.

There are a few reasons. Some of them are in the users' interest. Lots of people phrase their search like a question. "How do I turn off the wifi on my blue windows 11 laptop?"

While ignoring stopwords like "the" and "a" has been common for a while there is lots of info here that the user probably doesn't actually care about. "my" is probably not helping the search, "how" may not either. Also in this case "blue" is almost certainly irrelevant. So by allowing near matches search engines can get the most helpful articles even if they don't contain all of the words.

Secondly search engines often allow stemming and synonym matching. This isn't really ignoring words but can give the appearance of doing so. For example maybe "windows" gets stemmed to "window" and "laptop" is allowed to match with "notebook". You may get an article that is talking about a window of opportunity and writing in notebooks and it seems like these words have been ignored. This is generally helpful as often the best result won't have used the exact same words that you did in the query.

Of course then there are the more negative reasons.

1. Someone decided that you can't buy anything if your product search returns no results. So they decided that they will show the "closest matches" even if nothing is anywhere close. This is infuriating and I have stopped using many sites because of it.
2. If you need to make more searches or view more pages you also see more ads.

It's because websites interpret those characters differently because of how coding requires using the physical qwerty keyboard. Essentially ">" gets used as a compator operator in programming languages, which means that it's used as a tool to instructs the computer how to do things. When we need to display the symbol, we use ">" as an "escaped character" which basically means treat it as the symbol, not the instruction set. Often search engines will use a very powerful tool called a regular expression which looks like this for phone numbers: ^(\d{3})\s\d{3}-\d{4}

And each character represents something, ^ means start with. \d means digit { means 3 of whatever's in front of me }. Breaking apart the search parameters is pretty complex and it needs to happen FAST, so at a certain point the developers just throw away things that can be a security concern like special characters like &^|`"'* specially because they can be used to maliciously attack the search engine.

For other characters: https://www.w3schools.com/html/html_entities.asp