Objectifying women is considered bad form. It'd be like saying they're just a sub-class of Person.

I wouldn't have a problem with someone using males/females in a vacuum, but all too often I read men/females from incels and misogynists on the Internet, so now "females" feels derogatory by default.

Outside of a clinical/scientific setting? It’s comes off a bit creepy

Male/female toilets sound creepy to you?

Men/women - nouns

Male/female - adjectives

I think the reason male and female get equated with biology is because biologists need to describe individuals in terms of characteristics within the species.

Like, "I live with a small, white, female felis catus and a tall, Caucasian, male homo sapiens" is a weird way to tell people that I live with my cat and my husband outside of a scientific context.

This isn't as simple as you are implying as if you want to be a bro to trans people more nuance is generally required. Male and Female are not used strictly scientifically in context. Male and Female are often used as adjective forms of man and woman. Take the example of a male or female firefighter - if a trans man is a firefighter refering to him as a female firefighter using this reasoning comes across as fairly transphobic because it feels like you are either trying to utilize some sort of technical linguistic dodge to find an occasion to misgender them or your purpose is to out them to people unawares of their trans status.

Even when people use male and female as nouns instead of adjectives this transphobic reading applies because a lot of fairly obnoxious people will try and use these words as shorthand to imply that trans identities don't matter and to avoid calling you by terms that align to your identity or to isolate trans identify out of discussions. This is why you hear the phrase "Assigned male/female at birth" used by the trans community (though it actually originates from the intersex community) or "birth sex" to refer to groups that include non-binary people instead of just male or female. That linguistic abstraction is important because it implies removal by way of time. In trans terms one can be treated as female at birth given the assumption of cisness for infants implying that that term could be inaccurate in the present day.

By contrast "Trans Identitied males/females" is a transphobic dog whistle. "Biologic males/females" has the same vibe because from a scientific prospect the term is so bloody vague it is practically meaningless. The speaker is just trying to imply the social category is irrelevant or putting emphasis on an assumed physicality. Like if someone says for example "biological males in women's sports" you know the entire point they are going to be making is total exclusion before they even bother to elaborate further.

The reality is words Male and Female still represent social categories unless you append onto them more specific adjectives in term like Phenotypic, chromasomal or so on. These words are not immune from the cultural moment of negotiation of trans inclusion.