I just parental lock my wife’s phone and she parental locks mine. This has worked for us for nearly a decade now. Solutions that actually work often sound weird (because otherwise it wouldn’t be a problem in the first place), but yeah “ask my wife” and vice versa keeps us from installing Facebook and other apps that are rabbit holes while making it easy to remedy if I actually need it. To be clear, this is totally voluntary and we both choose our own blocks then say “hey add a password” or “hey I need to adjust, punch in the password”. I see it as similar to having a bank teller vs the ATM. Easy peasy and that little bit of friction has made our quality of life better.

In case you don't want to bother your spouse (or don't have one) you can use lockmeout.online as a simple online time lock service to hold numeric codes.