I want to to use a service for crash reporting and I see that there are a few options Crashlytics, Instabug, Bugsnag, Bugfender, Splunk Mint, Visual Studio App Center, etc.
I see Crashlytics is free but it even address items 2, 3, and 4? Do people use multiple tools?
I do not know in detail the rest of the tools you mentioned, so I prefer to keep my opinion to myself.
Disclosure: my answer might be biased, I'm co-founder of Bugfender.