That was true, though.

In 2018, a Venom movie got a 31% Rotten Tomatoes score, and made $856 million.

It was true if you didn't spend too much, DVD sales bailed out a lot of bad movies, but streaming doesn't have the same direct revenue.

I'm gonna nudge your sentence a little bit to make it sound both more realistic and much worse at the same time:
The implication here is that it used to be you could make a ~~bad~~ LAZY movie and still profit.

A bad movie can be full of passion, it can be an interesting failure.
A lazy movie is phoning it in; it has the opposite of passion; here is where all we see is suits with Ferraris and sycophantic (corporate ass-licking) writers and directors.

I admit prior to the pandemic I wouldn't have minded going to a somewhat mediocre but kinda entertaining movie as part of a night out. Now it is too expensive and the theaters are depressing shadows of their former selves and unless I 100% know a movie is good and can get 2-3 family members to agree I'm not going to a theater.

I think something else that has happened is the breadth of available media in the streaming age means it is easy for individuals to find a show or movie that fits their individual tastes. No compromise needed. I know in my house getting everyone to agree to watch a single show or movie is impossible. No way we're all piling in the car, driving through ridiculous traffic to sit in a dirty theater that smells like warmed over urinal cakes to watch something none of us are particularly interested in. Why do that when I can chill watching reruns of Stargate SG-1, my spouse is rocking Tik Tok, my kid is watching Twitch?

Movies as a collective experience died circa 2020.

I'm not even sure they believe their own words.

In the mid-2010s pretty much all of them would do incredible business

That puts us in "The Amazing Spider-Man" territory. While technically both films were a financial success, they were not well received critically. Sony had a whole plan for a Spider-Man universe following these two films.

If it had been such incredible business, they would have continued with their Spider-Man universe. However even at the time they knew they weren't up to the task, they knew they didn't have the quality to create a profitable Spider-Man universe. So they made a deal with Disney/Marvel.

THEN, for whatever reason, AFTER giving up Spider-Man, they still tried to create that Spider-Man universe, but without Spider-Man.

Unfortunately for all of us... Venom sorta worked. Sony could have their cake and eat it too. Except, as we saw, not really. But we could justify Venom 2, Venom 3, Morbius, Madam Web and Kraven, all by saying, "But Venom worked, it could happen again."