Antiracism is a religion.

Struggling to understand which race this is racist to. Ghetto is just an expression for a gross and beaten up area or person.

not sure in which context it is used in the US today?

it's not. anyone can be from the ghetto. i know some ghetto af white people.

Not that I know of tbh doesn't it basically just mean poor/ kinda trashy?

It's important to say and not say what people tell you to. It's really a simple act, that can make other people's lives much better.

I always thought about this word as a place where poor people usually live. I associated class rather than race to this word. However according to Longman dictionary it might also have racial connotations.
This is one of the definitions of ghetto in Longman dictionary:
"A part of a city where people of a particular race or class, especially people who are poor, live separately from the rest of the people in the city. This word is sometimes considered offensive."

depends on who says it. sort of like the word "queer" -- not everyone who uses the word is homophobic but you can almost certainly tell who is by how they use it

I mostly treat words like 'ghetto' and 'hood' as being about social class and status more so than race, kinda like the opposite of bougie - that said, it is hard to separate those two things, especially in America, so I understand how someone would hear the word ghetto and view it as an insult pointed toward black people

It’s not a word I’d ever use (unless I was speaking about the Warsaw Ghetto or something similar). My preferred term is “shitsville”.

Your roommate sounds like an idiot. =p The word is merely descriptive of a particular type of neighborhood, and without it you can't get that particular concept across. Acknowledging reality isn't racist.