How do you de-google yourself properly when every 3rd website stops working entirely unless you whitelist some google stuff in your content blocker?

1) "De-googling" doesn't need to be a binary, all-in or all-out situation. Any reduction in reliance of Google (or any single point of failure) is good. Diversifying the big stuff (mail, storage, etc.) is a great start. About last on the list is worrying about the occasional allowance for gstatic.com or whatever.

2) While I occasionally need to allow some scripts from google, it's absolutely nowhere near 1/3rd of sites.

I've de-Googled myself and this idea does not match my reality.

I've largely de-Googled myself, but not my family. The only Gmail I have is from a few old accounts that hardly ever email me anymore; I've been on Apple's email, calendar, photos, etc. for years, and use Kagi for search. Nor do I feel any pull back toward Google. The biggest involvement I have is for the correspondents I have who are still using Gmail; every time I email them, my stuff ends up in Google's system.

It is almost always blocking first party JavaScript and XHRs that causes breakages. I have rarely had to enable Google anything in uMatrix to get a site to work (more often it is Cloudflare), and it is only if the site insists on reCAPTCHA.