Here, let me show you something:
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This is from the Dark Souls board game.
Things like the action figures you talk about? They often dont really do anything, people who buy them set them on a shelf or something and... that's it.
But things like the characters and the big monster figure in the photo here? These arent made to sit on a shelf. They are PLAYED WITH. Moved around, knocked over, and many people who play miniatures-focused games (I just call them "figures") also like to take the time to very carefully paint them. And THEN play them in the game they are from. Games that involve figures like these often involve a LOT of them, not just a couple. I've got so, so many of these things, and that's JUST from Dark Souls alone. I could also talk about Zombicide, which has like 5 times as many of them.
I want to stress that this is not a kid-focused hobby. Good grief, no. This is a hobby that STARTS with adults, and if those adults are parents, they may try to get their kids into them so they can all play together (but if it doesnt work... that wont stop said adult from continuing with the hobby). Heck, many of these games would be a bit much for most kids, either being A: way too complicated, or B: way too frustrating.
Look at this:
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This has a wildly different vibe to it, yeah? It kinda LOOKS like it might be a kids game, but no, it aint. The rules for this would be a bit much for many kids (modern board games dont play at all like "family" board games), but also the game is very freaking hard. It's not competitive, it's cooperative (so, you and your team, or just you if playing solo, against the automated "opponent" which is in this case the flame & smoke things all over the board) and playing this one mean you're probably going to lose a lot.
Again though, little fire fighter figures being shoved around the board and bright colorful pieces everywhere.
Did I mention this hobby is for adults? Like seriously that's the target audience. Dont get me wrong, there are certainly games that are specifically family oriented (so, meant to be simple enough to get kids interested) but the vast majority of it is stuff like what I'm showing here.
It's a deep rabbit hole. Too deep. People get REALLY into these.
So... no, you're not weird for liking what you do. Figures and stuff like that, it's all fine.
This aint the 80s, where there was the bizarre hard divide between "kids' stuff" and adult stuff. This goes for video games too. Kids aint the primary audience anymore.
Beyond that though... look, there's no reason to worry about what others think of your hobbies and interests. Instead, worry about what YOU think of your hobbies and interests. And just have fun with them.
Incidentally I have a lot of non-board gaming figures and stuff myself as well, and things like plush dolls.