Looks like Pixelfed's growth spurt is slowing down. Absent any new external stimuli I'm guessing it'll stabilize around 200K to 300K monthly active users -- over a hundredfold order of magnitude from what it was just a month ago.
Pixelfed is definitely a good example of "its what you make it".
Try searching for and following some hashtags that you're interested in. I have an awesome home feed made up of art, design and photography hashtags and artists.
It has gotten really, really good for photography. There's a bunch of incredible photographers posting their stuff on the Fediverse these days, and they enjoy the appeal of it that it's closer to what Instagram was before it became an influencer hub.
As for random cats and dogs, I guess some people enjoy that as well.
That’s exactly me as well. Tried it, looked at random people’s cats and dogs. Not for me.
I think that's kind of the challange we've got with regards to making social media from a nerds perspective. We're a bunch of nerds that don't understand the appeal of the things we want to make alternatives to, and wouldn't be interested in using them even if they weren't run by horrible evil tech corporations.