Earlier quoted context omitted.
What kind of exercise? I run, row, lift and do various group PT classes. Running it’s essential for pacing and target HR Zones, same for rowing, and on the group PT they’re very variable in terms of what they’re targeting, and it’s good to know if I’m short on (an)aerobic workouts.
I think a lot of people exercise a bit less "scientifically". I tracked my runs for many years, but ultimately never did anything with the data, and rarely even referred to it for anything useful. I generally "track" the effectiveness of my exercise based on the end results: my weight, how I feel, how my body looks, etc., and I can generally tell by how I feel while exercising if I'm doing enough or if I need to exer…
I walked the exact same path.
For runnings and aerobic exercise in general I tracked for a few years my times, calories, heartrate. But indeed never did anything with that data, nor really used it as a benchmark.
After a while I was also pretty easily able to find and sit in a particular heart rate zone, without periodic feedback from my watch.
Of course you'd want that precise info as a professional runner. But for me it was mostly useless. My apple watch broke during a swim one day and I never cared to replace it. Haven't missed it once to be honest.
I still track my big compound lifts in the gym on my phone using a simple app, to track progress. I don't particularly do much with that data. If it's improving I'm happy, if it's not I'm a bit disappointed. But in any case I tend to go pretty hard in the gym, lifting a number of sets with a few reps in reserve, and try to increase the weights slowly. In that regard tracking a set helps to set the baseline for the next workout, that's helpful. But I still adjust based on how I feel that day, aiming to simply complete a few sets with a few reps in reserve (i.e. making it as challenging as it can be without sacrificing safety or unnecessarily long recovery). It's a constant reminder of how far I've come also, which is nice.