As has been said before many times, lifting heavy shit that has the ability to just drop you on your ass builds a certain character. When a weight stops being "scary" that character building ceases to continue.
I think the issue with the "how strong is strong enough?" question isn't so much that it deprives someone of the ability to live a more productive/meaningful life (I imagine most adult males can get through life just fine from a purely health and ability standpoint with a two plate squat), but because setting artificial ceilings defeats the purpose of why we train.
We train because by always trying to lift more, we are continually forcing our bodies and minds to adapt. Now as a practical matter, at a certain point we won't be able to lift more. Life stuff, work/family obligations, genetic ceiling, disease, injuries, getting older...there are a multitude of reasons why we may start plateauing or why getting stronger simply isn't feasible. As Sully says, at a certain point you have to sprint just to stand still.
But by always trying to improve, rather than designating some arbitrary ceiling as your stopping point, you ensure that you're always forcing your body to adapt as much as it physically can given your circumstances, and you're setting as high of a floor as possible for when factors outside of your control start taking over.
It's the same reason why people study furiously for major pass-fail tests (bar exam, boards, certifications, etc.). Sure, you don't "need" to score in the 90th percentile on any given pass-fail test (only 10% of test takers will actually hit that mark, after all), but by studying as if you need to attain the 90th percentile, you ensure that you're giving yourself the best chance of passing.
People who study only to pass tend to have the largest rates of failure, even though many turn out just fine. Just like people who lift only to hit an arbitrary number and then "maintain" tend to have the largest rates of losing strength, even though many will live happy, healthy lives at a decreased strength potential.
As has been said before many times, lifting heavy shit that has the ability to just drop you on your ass builds a certain character. When a weight stops being "scary" that character building ceases to continue.
I agree with your whole post for most of the people, most of the time.
But this mantra is not valid any more when we get to special situations, special people, special goals - to the extremes. And thats where this "stronger is always better" fails. For example, when pluripotent naively claims that if they would have this and that entry level of strength, EVERY sports team would wipe out others.
Thats simply not true: Ressources are finite for professional athletes and for some goals, it may very well be prudent not to dedicate most of them to strength training let alone SELECT athletes for their ability to reach high strength standards - you dont want to have 20 Eddie Halls walking around on a soccer field.
You also dont want to lift 7 times a week to your genetic (and thus recovery) limit bulking to the highest body weight you can when your goal is general health.
So thats where this blind "stronger = always better" fails: At the dogmatic "always".
Lets put there an "often" instead.
Even if I stall where I am and never get stronger, I will continue to pursue more strength because there's no downside to either the gaining or the pursuit of higher strength levels.
The greatest thing strength training has taught me is that I'm not fragile and, despite having serious genetic conditions, am not really special when it comes to how training stress affects me. Sure, I get sick more often that most (I think), my recovery shit, the time I have to train - both the hour and available days - abysmal, and my progress is glacial and troublesome when I make any progress at all.
In my view, the process of gaining and maintaining strength, in its very simplest form, comes down to persistence, consistency, and a program suited to your goals.
"Shut up and lift" under that framework, is sage advice.
Of course there are even downsides for someone like you who is not a professional athlete that needs other qualities or has finite ressources once youre very near your limits: What youre gonna gotta do when you stall with 4 days training/w? Well, you should train 5 times a week. If you stall there, then six, then seven. Then some days twice. You should gain weight, even surpassing body fat levels considered as healthy, cause that will give you more (absolute) strength. Some chronic injuries will occur, your immune system doesnt like permanent heavy efforts as well - so yes, there will be downsides. Try it out and report back if there are no downsides.