There's nothing wrong with using Reddit, Twitter, and other mainstream site still while being active on fediverse.
I see a lot of posts on fediverse trashing reddit, Twitter, spez, musk and so on, and rightfully so. But like it or not, the mass majority of users on the internet still use these sites, and some of us still want to interact with the friends and communities we are a part of on those sites. And there's nothing wrong with that either.
Personally, I want fediverse to grow, and I post on kbin and mastodon constantly, and try to grow the communities on them. But I still pop over to reddit for r/splatoon, r/casualconveration, and my hometown sub, because either the communities haven't grown enough here yet for constant fresh content, or the content is different enough between both to justify me checking in.
I get many are here as a protest against reddit, Twitter, or where ever else you came from, and that's valid. But there are many of us who are simply casual users who want to include fediverse into their drives of other social media, and that's totally fine too.
Unfortunately some of my niche interests are non-existent here...so I am going to lurk reddit from time to time. Not through their app though, just the site.
My own rule of thumb is - I'm going to lurk on reddit if I need to, but I'm only going to participate in lemmy and whatever other platforms I support. It's undeniable that reddit still has a treasure trove of information.