If sentryio has a self hosted version and logflare has one too, why would I pick logflare? Are there any differences? I tried sentryio and it's really convenient, at least the hosted version.
Depends on your use case. If the volume of data you're looking at is not much, Sentry is more feature rich and refined.
If you want to expose a logging interface to your customers and/or easily integrate large volumes of structured event type data into the rest of your infra, then maybe look at Logflare.