Yep, some people seem to have a proclivity towards thinking that whatever is (or seems) disadvantageous to them (or a group they identify with) is somehow done on purpose by someone/a group that will profit from the said thing.
But if you think about it, it doesn't even work here. First of all, no one can tell you that your battery has a poor capacity, because you test it daily. And people are pretty sensitive to this issue, because we have tricked the manufacturers to create phones that have just enough capacity. (By requiring faster phones, larger, better screens and thinner phones. And not requiring a battery that lasts much more than a day.)
Actually that 'narrative' has the opposite effect: there are a lot of articles online that tell you how to enhance the life of the batteries. (Whether it's really needed or not doesn't make a difference.)
Regarding charging it from 50%: this is not something that hurts Li batteries. Actually it's better than allowing it to drain (or go into some unspecified low percentages, probably below 20 or 10). Charging to 100% is said to have a negative effect. I mean it probably wears faster than if you charge to just 85%.