I posted some thoughts about F-Droid clients and maintenance in response to a post, I'd be interested to hear what other people think: https://www.reddit.com/r/fdroid/comments/noov58/the_problem_with_the_fdroid_clients/h0aobs7/ @fdroidorg
I don't share/experience the mentioned issues.
Other then that, it's the standard issue with FLOSS projects: too few people actually contribute. And that includes people paying money so one (or more) devs can work on sth and get payed for it.
Separation of concerns by splitting the code up in sub-projects is useful and may lower the barrier to entry.
But someone still needs to get payed or have an excess of free time to do it, which brings us back to the previous issue.