The best way to tune the algorithm on Youtube is to aggressively prune your watch/search history.
Even just one “stereotypical” video can cause your recommendations to go to shit.

Is there anything the rest of us can do to cultivate such a mindset?

For cardio it’s basically “go slow”. The main source of discomfort is the exertion.
An easy long run with good music is quite meditative and enjoyable.
When your legs hurt and you’re wheezing your lungs out, not so much.

Running, not so much because my calves tend to seize up and it gets a little painful

This is often a form and/or a shoe type issue.

Doing it yourself is fine as an educational exercise for newbies, but skilled linux users generally have better things to do than to do the setup by hand for the nth time. On the other hand the “vanilla”/bleeding-edge approach of Arch makes it one of the best bases for derivative distros available, so basing your distro on it is a no-brainer for many.

Twitter probably opened the floodgates when they managed to shaft users and cut API access without outright killing themselves. Now everyone else is emboldened to ask “why can’t we do that too?”.