It's fun! Tumblr has been basically singlehandedly supporting the textpost meme industry on Instagram for years. I like that Tumblr tends to tilt toward text rather than words images; here's my favorite example of that:
If you're thinking of joining, the #1 thing to remember is to reblog (and optionally tag) things you like, not just tap the heart icon. Tumblr is for curating a blog of things you like, and if you don't reblog anything, you look like a bot and you will get blocked. Also, likes don't actually do anything for the algorithm; likes are more like "save for later".
You decide your own algorithm, to some extent, by hitting Follow on people whose blogs you like. I like that. I think it might resonate with Lemmy users too :)
Usually bots are created with minimal effort. They post porn or affiliate links or something, and then they spam like / follow people to get people to click on their username and view their blog. They get quickly banned, and then they come back with another username. Shitty little pornbots.