Depends on your goals and what you enjoy. It's entirely possible it's just not the game for you, which is fine too. Everybody has their preferences and likes/dislikes with games.
As far as Minecraft goes, it has a few different gameplay loops. There's a whole survival aspect where you build defenses to protect against bad guys. Maybe do that in interesting and unique places like the nether. There are bosses and an endgame as well for people to work towards.
Some people like redstone and making complex automated machinery with it. Even without mods there's a fair amount of interesting factories, machines, sorting, special effects, etc you can do with it.
Others enjoy the building - maybe they make a replica of a giant cathedral, or the USS Enterprise in 1:1 scale, or a whole city, or their own house. Basically a virtual lego set.
Plenty of other things too. Social aspect where multiple people can hang out and chat with some extra stuff to do while doing so. On mobile it's probably one of the better experiences that isn't a completely shitty p2w/mtx laden mess. It can be a great way for parents to play games with younger kids. Tons of interesting mod packs that can transform it into various things whether it's single-block challenges, Factorio-esque automation games, fantasy swords and sorcery RPGs, whatever you want.
Anyway, nothing wrong with it not being your thing, but there is genuinely a ton of different things you can do it in that a lot of people really enjoy.