With current synchronisation problem between instances, choosing a big instance is a no brainer. I don't want to use small instance and got 404 when searching community on other instance or when not all comments from other instances showed up.

I use Gboard because the prediction is better than the others. As a Japanese speaker, the choice is limited.

I can't bring myself to uninstall Sync.

Realistically, this will end like Twitter migration. Some going to move, but most of them still using Twitter (or Reddit).

not enough of those famous and important people moved from Twitter to Mastodon

This is the reason I'm still using Twitter. I use Twitter not to tweet about what I did, but to get news from people I follow.
Tech people can move to Mastodon because their circles are moving, but not with common people.
For me, personally, Mastodon is like empty void. No one to follow and I can't interact with people who share same interests because they only exist on Twitter (since the "famous people" isn't moving from Twitter)

So it's basically you pay to Reddit yet without the perks of Reddit premium. You pay just to use 3rd party app.

If their phone stuck in Android 11 in 2023, I doubt there will be any updates from OnePlus.

It's on the homepage. Looks like it's not compatible with Firefox. I can't reproduce it with Vivaldi.