Sure, Amplitude is awesome.

But what about these open source self-hostable alternatives?

You may want to check by yourself: PostHog.

1. Install

   PostHog

   The single platform to analyze, test, observe, and deploy new features

   ★ 22.4k Analytics Product analytics Feature flagging A/B testing License: MIT Expat

   PostHog provides open-source web & product analytics, session recording, feature flagging and A/B testing that you can self-host.