That would've been too easy - instead it's now used in fewer places, but with new rules ;) When it's long-pronounced, ß is still used, like in Fuß or Stoß. In words like Fluss it's replaced with ss.

Not entirely. The spelling reform (about 10 years ago) somewhat reduced the use of ß but you still use it frequently after a diphthong (as in "Straße" [street]).

That's just a long vowel, not a diphthong (literally "two sounds"; incidentally, "sounds" has a diphthong in it).

I started living in Germany right after it was adopted, and still cannot get the long vs short vowel history for ß.

They just sound the same to my hears, so I got around it by memorizing the respective use cases.

I tend to still write in the old spelling (I didn't have to take exams in the reformed spelling yet so I never bothered to memorise all the braindeadness) and rely on Word/Outlook to correct me where necessary. That works quite well so far.

It might depend on where you live. I took a recent trip through Germany, Austria, and Switzerland and I noticed that Austrian street signs tended to use "Straße" while German and Swiss tended to use "Strasse".

OTOH it could also be just spending priorities of updating street signs vs. other things.

I knew nothing about the phasing-out of ß until reading the comments on this article.

> German and Swiss tended to use "Strasse".

In Switzerland, "ss" is standard (Duden says: "In der Schweiz kann das ß generell durch ss ersetzt werden <§ 25 E2>.") I haven't seen "Strasse" on signs in Germany, but there might be regional variation (since street signs are a local-government responsibility)