Have you tried putting your phone in "grayscale" mode? Works wonders for turning your smartphone back into a "tool" instead of a "toy".
However, the thing that finally did the trick for me was something called "brick" (https://getbrick.app/). It's basically an nfc tag, that works with a tiny app that uses Apples screentime API to either allow/deny list specific apps or websites. Once "bricked" you have to physically scan the NFC tag device to unlock those apps/websites. I used it to block the things I found detrimental, but which were too difficult to completely remove from my life. Then I put the device in my car.
Keeping it in the car makes scanning it a bit of a chore. Which means I have time to stop and think about it on the way to the car. This forces me to make a conscious choice, rather than automatically reaching for the phone every time there's a dull moment.
I hear there's another similar device called Unpluq that has more features, and works on Android as well, but I think it comes with a subscription fee. Brick is more just a "thing you buy once".
So even if I got 3 text messages, 2 missed calls, and other random notifications, the bar would show only one notification, and I would not get a sound/light. You'd have to click on it to see the actual notifications you missed.
You could, of course, have whitelists to let certain notifications through.
Best. App. Ever. It's great to be able to work or do whatever for hours, knowing that your phone can't interrupt you (unless someone calls, which they rarely do).
Sadly stopped working after some Android update. I'm sure there are similar apps, though.
And if the app is good, it will categorize it's notification types in a user-centric way and allow you to enable only specific categories.