Earlier quoted context omitted.
As multilingual user constantly switching between 3 languages, that's why I fully committed to the US_intl keyboard layout a while ago and ditched the abomination that is QWERTZ. Took a while to get used to, but overall it has been a very noticeable improvement. One layout to cover all languages, no more constant switching. Edit for clarity: I type "a to get ä and 'a to get à. If I want to type actual quotes followed…
How do you type ä ö ü ß ?
right alt + q = ä
right alt + w = å
right alt + s = ß
right alt + y = ü
It took a day or two to get a hang of it but it's such a relief not being constrained by everything being developed for US layouts