I am far from any type of racer, but have been training with power for 4 years now and use TP, STrava, Garmin, and WKO.

Honestly for what I do, strava premium works fine. I can track my power over segments, entire rides etc. They have a version of the performance chart thats good enough in my mind for average cyclist just trying to improve.

That being said I still keep my training peaks premium account. I track my weight, fat percentage and of course workouts and rides there.

I rarely use WKO anymore.