Yes, still relevant. Many of these tools have a server SDK or API to report events to the analytics engine. You can use this to report events from an integration.
So basically you define an event “Recipe run” in the analytics system, and then every time your block does something, you call the “track event” API with this event and any other data you want to include (automation ID, user ID, etc).
You’re right that many analytics tools integrate more “out of the box” with frontend apps – for example, you can install a tag and get 1000 data points for all your customers.
But from my experience many of these metrics aren’t even relevant to a marketplace app, so even frontend apps need to create and report their own custom events.