What you’re asking for has been available for years. The answer is to swallow your pride and have a friend set up parental controls on your phone and safeguard the password from you.
No worries, I’ve made this suggestion to a lot of people but no one has followed through with it afaik, not even me.
I do find that https://freedom.to/ is one of the few things that has worked for me. It’s more difficult to bypass than ScreenTime, and syncing blocklists with the laptop during the day is great for overcoming procrastination. It works through a VPN profile (though not an actual VPN), so it also blocks apps.
I‘ve used it with schedules that go from 05:00 to 19:00 and it’s just such an eye opener when even a week after implementation I still open safari and reflexively type the urls for Twitter, hacker news, and Reddit even though they’ve only produced blank pages for days. Restricting it to the evening and going a couple of hours longer than the workday means I can still enjoy some mindless surfing but if I get busy doing something else I’m less likely to get sucked in. I also really like some of the suggestions here to restrict time wasters from the phone completely and only do social media stuff on the desktop. The extra effort for me to go to the office would mean that I’m more likely to use the time doing something else.