It doesn't have to be some privacy focused security super encrypted email service if that doesn't fit your use case. Use outlook.com, fastmail, proton, try one out for just shopping accounts that you check for orders and shipping etc. I get that we should have privacy and outlook isn't any better than gmail but I'm just not an all or nothing kinda person. If you're cool with what it offers and what it takes, then try it out.

Note that I use proton, paid member for 4 years and going. Happy with service. My point is that you need to pick the right tool for the job.

My choices are more about not having everything on Google (or being let down yet again) than my fear of google knowing I emailed my accountant two months ago or that I bought a dog poop scooper from Amazon.