Tumblr is a blog site. It is designed for quick posts that people scroll through quickly. Fanart and dumb memes do well on this platform, anything that requires more time to read/look at doesn't. Building up a following is very difficult, most people just want fanart and memes. Even if you make something that hits 16K notes, that doesn't mean people will give a damn about you or your other posts.
People will sometimes fuss about the "harassment" on Tumblr. For this I say, if you avoid politics and hot button issues, you will be OK. I once got hassled by some pro-gun loonies because I made a post about being anti-gun. If you get dumb anon messages from angry people, just ignore them. No one hassles you solely for being white, male, cis, or straight unless you are being racist, sexist, homophobic, or transphobic. For the most part, people leave you alone. There are some "edgelords" on Tumblr, sometimes you have to be careful of them.
Tumblr also has a lot of porn bots.