Also, an underappreciated role of muscle mass is as a giant store of emergency amino acids.
Stronger in the non-important (for the activity) parts of the body makes it harder to be stronger in the important parts. And also there are many ways to be strong, as in not all muscles are the same and also your neurological ability to control your muscles may also very widely .
Also powerlifters have much less impressive bodies than bodybuilders, and without pump and proper lighting you will generally might not even recognize that a person is top powerlifter.
Powerlifters have incredible muscle mass, they just aren’t picky about covering it with body fat because it doesn’t make sense for the sport. The main reason bodybuilders are weaker is that their caloric intake is much lesser (especially at meet prep when they sometimes are practically starving themselves to death).
They could easily add a few top sets of higher intensity work with low reps and get much stronger.
OTOH weightlifting is still an activity performed for show, not practical tasks requiring strength. Equally, a Lamborghini is still a pretty nice car, and a Tissot watch is still a precise mechanical watch. But it's not the point.
By contrast, a police car does not look like a super-fast car, even though it's very fast. Equally, most Marines don't look like bodybuilders, even though their job requires exceptional athletic prowess.