i mainly just use letterboxd, and the way i use it is more like a casual journal rather than something that would be useful for other people to read (and i state on my profile there that i'm not trying to give objective critique at all)

the other place i talk about what i watch would be in chat servers and even then i don't like to get into the weeds with discussion too much, if someone asks i will give them my opinion and maybe if i am interested we might talk about why we disagree on certain things but it isn't something i want to spend a lot of energy on