you can screw up your body in numerous ways if you overdo it, ie grow enlarged heart, screw up joints or spine and end up semi-disabled relatively young. just look at pro lifters, most of them after career end up obese with various health issues, some barely able to walk or lift anything more than sheet of paper.
it's a think line to walk, unique to each of us, where you try to grow as much as you can without crossing it
That is what I failed to emphasize - it must be "just right" - not too much and not too little - optimal - slightly better than good-enough.)
Not always. Things that don't kill you immediately may kill you in the long run.
In the long run, we all die anyway. It's not necessarily unreasonable to evaluate one's options on a quality vs. quantity basis.