The key is that there can be no "slowly leaving." I went absolute cold turkey. I maintain that there is no other way. Not only do most people not have the self control to be able to moderate themselves, but reddit's structure and algorithm are specifically designed to try to suck you back in, keep you enraged, and keep you scrolling. Because Enragement is Engagement™.
But reddit and its various decision makers went out of their way to piss me off multiple times, as well as tons of other people, so I left. I consider myself a pretty rational and level headed bird, and I made plenty of contributions. But the message there was clear: They don't want people like us there. They want vacant eyeballs they can market at with bots. That's what the new shareholders demand.
I have not found that my life has been significantly less enriched without reddit being present in it. Rather, much the opposite. All the inevitable bickering, the arguing with idiots, the whole thing about having to walk on eggshells or appear to espouse a particular approved dumbass point of view or else you'll be brigaded with downvotes or randomly banned; it turns out none of that is productive. It's not even, if we're honest, really engagement.
I find I have more hours in my day to do something else instead. I'd rather do something tangible, and here I can share it without having to be concerned about whether or not my contribution will be approved by the hivemind.