Slay the Spire does not have subscriptions, loot boxes, etc. so it can optimize for balance, instead of engagement or play time. It's very much the exception.

The risk of analytics is an erosion of your design and vision. You just do whatever makes the numbers go up in the short term.

Valve did this with Portal!

Or at least I feel like they did after playing through the games XD

The games theme felt like a giant analytics test where everything was noted!!

I'm sure Portal was heavily playtested but it hasn't significantly changed after release so there is no reason to believe that they are making changes based on player analytics (even if they are collecting at least some via achievements).