You don't have to torture yourself though, same as you don't have to one rep 450lbs all the time.
I mainly do easy 10k runs with some (for me) faster 2,5-5k when i feel like it and never felt the urge to do races, not even in primary school when i was quite good at “longer distances“ (which basically meant 800m back
I do it because i like it.
For me, the biggest torture regarding running is stretching my hamstrings ;)
But i also do body weight training for years now, which can be plenty of challenge for most, except for your legs, where additional weights are required really fast if you want progression.