A while back I built out a quick guide comparing all of these alternatives, because the core value prop was pretty similar and it was annoying to compare between pricing plans. (My personal vote goes to Fathom.)
Fathom is run by some goofy marketer who has openly slandered (on HN) other analytics products in this space. Sadly, can’t support anyone who does that. They’re not open-source either.
No SEO effects. If anything there could be a slight advantage to using Plausible over GA because the JS tracker is much smaller, though in practice I would not expect any SEO impact.
Plausible is much simpler than UA, all the reporting is on one page and it has much more limited config options. It also can import your UA data. If you're looking for a simplified GA alternative it's a very good choice. (Full disclosure, I recently published an article on their blog about UA vs GA4: https://plausible.io/blog/ua-vs-ga4)
You've probably already discovered this, but the only way you drill down is with filters. You can ad-hoc define a page filter with multiple URLs, but you can't (to my knowledge) save that filter set, and content grouping UA-style doesn't exist. Their live demo is with their own site's data: https://plausible.io/plausible.io
"GA's interface is complex and confusing, especially for basic use cases."
As I said in another comment, it's been eight years since I used that accursed interface, and I'll be ready to try it again once the flashbacks go away.
I'd love for you to add Amplitude (amplitude.com) to your guide. Ensuring we have the same easy out of the box experience GA does is a top priority for us this year. Let me know how I can us get added!
https://buttondown.email/comparison-guides/google-analytics-...