O V.

TL;DR it's a good website to vent in, but there's a very dark catch.

If your question is "does this platform serve its purpose", the answer is yes. It indeed lets you vent anonymously about anything you want, whatever the topic. I do recommend using it if anonymous venting is what you're looking for.
HOWEVER,
I do want to offer you a word of caution: First of all, everyone posts as they wish, whether you like it or not. If you browse certain categories or spend enough time on the front page without filtering them out, you may (and will) run into remarks that there's a risk you will find offensive or triggering. I believe some of them are trolling and some of them genuinely hold those worldviews. Reaction to them or lack thereof is entirely up to you.
Secondly, while posting, if you set your comment permissions such that everyone can reply, you should be aware that you grant this permission to the aforementioned problematic audiences as well, but I will add the extra warning that if you vent about another person in your life (especially if in 2nd person pronouns) there are some users that will reply to you as if it's them. If this happens please consider all possible scenarios and don't rush to assume it's actually the person your post is about, especially if they are being rude to you.

So, if you tend to get impacted by online strangers very easily I'd advise against using this website. But if you trust yourself not to take 100% of what others write there to heart, then definitely give it a chance