It's just another example of engineering being rushed and pushed. Not be confused with shoddy engineering.
At some point it comes down to the definition of what object you design and what the competitors do - for which price.
It doesn't matter whether it's a Boeing 737 Max-8 or a MacBook- the engineering team got pushed and forced to roll out something half-assed. They don't have the luxury of time and people to do an excellent job.
One of those is more vitally important than the other. Not saying that burning consumer electronics are no problem, but failure due to liquid damage is a questionable definition when it was not sold as resistant to such.
Others made it a key selling feature that their new phone-a-mathing is actually waterproof - and charge extra for it.
If it wasn´t water, it could be soda, the bath tub or saltwater. If it was not the high voltage backlight, it could be the battery terminals. It is simply not a matter of a bit more isolation here or there, it is a question of which requirements apply during development.
Could they do that? Sure they could do that, but for who?
Problems become evident months or years after the release date, and by then the corporation has forgotten what caused the design to be substandard in the first place.
I like watching Louis´ channel and apart from the right to repair movement, i kind of get the impression that the point he is trying to make might either be biased by seeing mostly the defective units - not putting them into the relation to all the working ones that survived other incidents, or just beneficial for him to put the blame on the manufacturer, as he is the contact for customers of his repair service ("do not spill liquid on your expensive piece of consumer electronics" does not work that well as a sales pitch).
And then of course there is youtube as platform to discuss it on, which is what it is, but there is this attention economy thing - intentional or not.
Mr. Rossmann is pointing out how Apple is blatantly failing at making their products better.
Based on an arbitrarily chosen definition - not product description, normal use or being advertised as such. Which pieces of consumer electronics do you expect to be waterproof?