Except I'm saying my experience is the opposite of the problem you purport. I (as the consumer) have always done "pip install whatever", and have never run into issues.
One of the commentors above explained what the problem really is (basically devs doing "pip install whatever" for their dependencies, instead of managing them properly). That's more a problem of bad development practices though, no?
Nah. That's a dumb UI. If you do cargo add whatever, it does something completely different from cargo install whatever, and there's no way to inadvertently use the wrong one. If pip install whatever leaves your project in a state that may be unusable for other people, but usable for you, that's just design that invites confusion and works-on-my-machine syndrome.