Gmail seems like the easiest piece of the Google puzzle to replace. Different calendar systems have different quirks around repeating events, you sometimes need to try a variety of search engines to find what you're looking for, Docs aren't bug-for-bug equivalent to the Office or iCloud competitors, YouTube has audience, monetization, and hosting scale... Gmail is just "make an email account with a different provider and switch all of your accounts to use the new address." They don't even give you that much storage for free Gmail; it's 15GB, which lots of other email providers can match (especially paid ones). You can import your old emails to your new provider or just store them offline with a variety of email clients.
Is updating all of your accounts (and telling your contacts about the new address) what you consider to be the hard part, or do you actually use any Gmail-specific features? Genuinely curious, as I tend to disregard almost all mail-provider-specific features that any of my mail providers try to get me excited about (Gmail occasionally adds some new trick, but Zoho Mail is especially bad about making me roll my eyes with their new feature notifications).
2-3 spam emails slip through every week, and sometimes a false positive happens when I sign up for something new. I don't see this as a huge problem, and I doubt Gmail is significantly better.
I agree with the other commenter, I use Fastmail and I get very few spam emails, most of which wouldn't have been detected by gmail either because they're basically legitimate looking emails advertising scams. I have a Gmail account I don't use and it seems like it receives about the same amount of spam, if not more.
1: https://www.cloudflare.com/en-gb/learning/email-security/dma...