Here's a crazy idea: Don't use analytics at all but focus on your product. If your success relies solely on "improving conversions" by tracking your users and then changing the position and color of your "Checkout" button then maybe try setting yourself apart such that customers want to buy your product even despite an obnoxious purchasing flow. Only then start optimizing it. More serious thoughts: Google Analytics i…
Here's even crazier one: Just do analytics on the backend instead?!
You don't need GA, nor 3rd party tracking cookies, just a simple session ID and a proper web-server's log analyzer, and you can get almost all of the same metrics.
You can nowadays even sniff on clients' screen resolutions and other browser details using just img srcset, css and log analyzers.