It may not be for everyone. Lemmys growth has stalled out and barring musk buying reddit and turning it to shit i don't see another influx coming. So we're kinda stuck with the community that exists now. Its a pretty good and sustainable community which can provide a lot of general interest posts like news, memes and cats lately. But for other more specific topics if if it's not already a large community here it probably won't be. It's not even just niche interests, professional sports for example has very little presence on here as a whole much less individual sports or teams, and I don't see, for example, a baseball community taking off here no matter how much effort you put in since the current lemmy community isn't much interested in it and your average baseball fan probably won't be coming to lemmy to discuss things.
My recommendation would be to use lemmy for some of those general interest topics, and maybe some of the more popular niche communities if your into them, And go to other places, preferably independent forums or rss feeds, for other things. We don't need one unified scrolling app, it may be a bit more convenient, but the internet is better off if you spread your traffic around.