I was always a measurement-free kinda person, but got bit by the Strava bug a few years back, letting it run silently in my pocket. In 2018, I got an actual computer. In 2019, I added a heart rate monitor. I've found both additions have been helpful in improving my performance...and since I like going fast, and I like a good workout, it's improved my enjoyment overall.
But! The major change I made this year that really improved my enjoyment (and actually my performance) was to eliminate myself from the Strava leaderboards. I'd gotten sucked in to the point where I actually cared about segments, and segment times, and all of that added a lot of stress to riding. It's still great to hit a PR on some climb or flat stretch - but all that is completely unrelated to the purpose of the ride (which is to go fast, or get a good workout, or just spend time with friends.)