Years ago I started "leaving" facebook by just: not visiting it. I didn't delete my account, I didn't explicitly posted anything announcing what I was going to do. I just stopped visiting it.
Now, it wasn't a trivial as that, because facebook will notify you, will email you, will send you messages reminding of everything I was missing out. So, along with the decision of "leaving" facebook I had to manually go and disable every way facebook could reach my attention. It took a while but it wasn't hard: I disabled email alerts (or just filtered them straight to trash) whenever I received one. For years I didn't have fb or messenger apps on my phone, or I would just disable them if I couldn't remove them. Now, with more granular control over notification I may install them but disable notifications entirely. In fact, I take a similar approach to email. While I do receive visual notifications of email, I don't get sound of vibration. In fact, my phone is in silent mode practically all day (I do have some rules that allow certain calls to breakthrough)
To me, gaining back control was about removing the ability of apps (and people) to digitally reach me whenever they felt like. And this is the core of my attitude with "leaving" social networks: it's about controlling when I want to actively use them (as little as needed). So, deleting account feels (to me) as I gave up having control (and extracting the little benefit of a network).
Also, it's not just about control how apps reach us.
It's also about establishing the social boundaries with friends, family and acquaintances: socials networks are NOT how you can get my attention. you may get my attention, but don't count on it. if you really need to find me you probably know how.
I still extract value from facebook/ig/linkedin on my own terms. But those companies probably get much less value out of me given their business models. I feel it's alright. In fact, I feel (maliciously?) better in this approach.
I still get linkedin job offers, and I do respond to them, probably after a few days when I feel like checking.