The key issue seems to be the 80/20 rule.

The 80% are anonymous lurkers or accounts that very rarely post anything.

The remaining 20% is split 15/5, with the former being frequent contributors to discussions - and the final 5% being _content submitters_ .

The 5% power users interact via 3rd party apps because, quite frankly, the "official" UIs (App, Website) are totally shite.

They also maintain the automated tooling to keep order of communities - again, accessed via API.

Without the 5% submitting content, the 15% won't interact and provide the remaining 80% material to read.

No material to consume = no advert page impressions = no revenue stream.

Most of the other popular apps are also shutting down and the official app is garbage.

If I can't use Sync I'm not going to use reddit.

Almost all, if not all, third party clients are closing down, not just Apollo. The only option is a badly designed ad ridden experience now.