I don't remember many events from 1996 but my German boss walking into the office excited about the spelling reform of "Schiffahrt" certainly stood out as a memorable event.
Context, maybe just for others: Schiff is ship and Fahrt is ride, so eine Schifffahrt is a cruise (and without the article, it is also the term for seafaring in general). Anyway, you can see that Schiff ends with two Fs and Fahrt starts with one, so if you put them together to form a compound word, you get three Fs in a row, Schifffahrt. In pre-reform German spelling, this was deemed excessive, so one would write Schiffahrt, instead. The German spelling reform in the mid-90s changed this, so now you do the logical thing. (Whether the old way really was confusing and which way is more aesthetic are separate questions.)
Impartial foreigner here who has no stake in the old or new spelling. If you're combining ship and port, you can't just write shiport. Of course it's shiff-fahrt / shifffahrt? By what logic does anyone argue anything else?
Once upon a time we used to write by hand. It was considered time consuming.
Once upon a time we used to set books in lead letters. There were ligatures, where two consecutive letters hat a special spacing - like "fi" or "sz". If we allowed three consecutive letters, we would need to invent new ligatures.
It is probably easier/cheaper to just forbid the spelling.
First of all, it was probably a descriptivist move. What I think happened is that people wrote 'ff' because 'fff' looked like a typo or was less convenient to write, so the linguistics codified that.
Also, there are portmanteau words where the middle letters overlap, e.g. bro+romance=bromance.