These are some really useful suggestions!

I have organized my phone similar to your three-tier system, but with a couple of differences. In my opinion, my approach is less “sexy” but pushes productivity even further.

1. Lock & home screen are both monocolor black. That’s it.
2. Apps that I use daily go on the front screen, the rest is in folders sorted by area of application (e.g. travel, cryptocurrency, shopping) on the second page. I don’t open the second page more than two or three times a week.
3. The only notifications I have are for WhatsApp and mails.

I aimed at making my phone as boring as possible in order to reduce the time spent on it. So far, it worked pretty well.

Thanks also for the app suggestions, might try out one of these.