As long as there's a logged in session somewhere, I have to have various tricks and extensions on my browser to manage things.
Most have been only varying degrees of successful, often ending up in me just disabling the feature whenever I want to get my fix.
The most successful iteration I've found so far is keeping these apps uninstalled from my phone, and using https://one-sec.app/ to forcibly install a barrier between me and the site.
It's not too much different, and the wait time can be customised. You can still just learn to wait through it, but importantly it also has an "intervention" feature that will block you off after a chosen time period and re-prompt you if you want to stay on.
It's been quite flaky on Instagram on desktop, but it's been very useful for Youtube on mobile (which I keep to play videos in the background sometimes).
Otherwise, Unhook for Youtube on desktop also helps blocking things like the home page and shorts.
I haven't found any extension for LinkedIn that works for blocking the feed (or at least suggested posts), and Facebook ones are sporadic in which work for me or not.