Reddit is old enough to vote and has several orders of magnitude more users. You can't create that much content organically overnight. As more content gets added it will attract more people who are interested in that content. In turn those users will contribute even more, even if it's just in the form of engagement and upvoting posts they like.

Lemmy is already experiencing some growing pains because the decentralized, user hosted nature of the platform will never be able to react quickly across all instances. We deal with it because we don't want to be controlled by one overarching entity and this is the ONLY alternative. Are there issues? Yes. Are there fewer issues than other social media sites? I don't know, but the problems are at least different and potentially more fixable in the long run.