Both Plausible, Fathom and GoatCounter are privacy respecting alternatives to GA. However, all JavaScript based analytics are blocked by lots of people, so they’re not that accurate. They’re indicative at best.
Then there’s web log parsers, like AWStats. They catch everything, which is where another problem comes in. Crawlers. Many of these tools try to rule out web crawlers, but never catch them all, so these tools tend to over inflate your visitors numbers. Once again, they’re indicative at best.
I’m currently using Netlify Analytics on my site, which uses logs, but I’m thinking about cancelling my subscription and just being blissfully unaware of who’s visiting my site.
GA is good at tracking traffic sources, and that's all I need. Plus, there are tons of materials on GA out there, so even a noob like me can install and use it.
What I like about Amplitude is that it's event-based. You can analyze users' behavior with it.
For apps, just give in and use Firebase.
I still have a lot of features planned, but I do enjoy using it more than any other platform (I might be biased because I made it though).