If I wanted to use Reddit/Twitter/etc, I wouldn't have deleted my account on those two platforms. Definitely don't want the fediverse to go that direction.
But I personally believe the problems with those platforms are 100% the fault of the people running the place and the bad decisions they have made in the past and will continue to make in the future.
I think a karma based ranking algorithm, designed by a community that has the right intentions (find good content, and sort it at the top), will work well. Also I think the fediverse is uniquely able to find the right algorithm because each instance can potentially run a different ranking algorithm.
The same way some instances have "vote down" and other instances only have vote up. Time will tell which approach is better, and all the instances will surely adopt the best one.