A succinct way I’ve framed the split is that a front-of-the-front-end developer determines the look and feel of a button, while a back-of-the-front-end developer determines what happens when that button is clicked.
Doing it right requires a different pace of working and a much broader thought process than “ok, let’s get this thing out the door.” Which is super tough because most workplaces place a huge emphasis on getting things out the door, and fast. Little agile tickets that are expected to be completed in micro sprints to me seem to be antithetical to doing it right.
I want you to consider instead the possibility that Waterfall came to exist, and continues to exist, for the convenience of managers: people whose methods are inherited from military and civil engineering, and who, more than anything else, need you to promise them something specific, and then deliver exactly what you promised them, when you promised you’d deliver it. There exists many a corner office whose occupant, if forced to choose, will take an absence of surprises over a substantive outcome.
Features don’t work, in the sense that they can be easily gamed. A brittle and perfunctory implementation, done quickly, is going to score more intramural brownie points over a robust and complete one. If the question is "does product A have feature X?" then the answer is yes either way.
We use the term feature factory as a pejorative to designate companies addicted to adding features, while accumulating incalculable so-called technical debt. This situation is driven by management for the convenience of marketing, and I am skeptical that a more faithful application of Agile principles will correct it. Indeed, I suspect Agile processes are constitutionally vulnerable to this kind of compromise.
The presence of a feature can only indicate to a user if a goal is possible, behavior will determine how painful it will be to achieve it.