I degoogled back when they announced AMP email, and am in broad agreement with the author here. The only things I’ve found it hard to replace are YouTube, Arts & Culture, Google Books, and Books ngrams. Everything else has great alternatives to move to 100%, and Books is just a backup alongside archive.org and Hathi.
Even if you just stop using one piece of Google you’ll find yourself in a better place.
What have you done for email?
For me, Fastmail has been incredible.
I concur on Fastmail. I only keep a "legacy" Gmail account for parental tech support.