Yeah, there's a decent chance you'll be stuck with crappy internet as a result. I still remember quite a few of my employers getting frustrated that fibre internet wasn't available for the building they were renting office space in, despite them running a tech company that really needed a good internet connection.
You are going to get so many blank stares at many shops building web apps when suggesting things like this. This kind of consideration doesn't even enter into the minds of many developers in 2024. Few of the available resources in 2024 address it that well for developers coming up in the industry.
Back in the early-2000s, I recall these kinds of things being an active discussion point even with work placement students. Now that focus seems to have shifted to developer experience with less consideration on the user. Should developer experience ever weigh higher than user experience?
Developer experience is user experience. However, in a normative sense, I operate such that Developer suffering is preferable to user suffering to get any arbitrary task done.
The biggest Soviet I've heard about this abbreviation is to not use it, since users do Nazi what it stands for.
But I'm thankful that you wish it on your greatest enemies - us
I always test my projects with throttled bandwidth, largely because (just like with a11y) following good practices results in better UX for all users, not just those with poor connectivity.
Edit: Another often missed opportunity is building SPAs as offline-first.