OK, here's the historic progression: Simple system came first, and is basically an open hole clarinet that only had a couple of keys for accidentals. This illustration is a little late, but shows a 5 or 6 key instrument dating to the early 1800's. It would've been comfortable to play in 4 or 5 keys...anything beyond that would be challenging and a bit uneven in response and intonation....which explains why they used to come in sets!
Albert system is still alive and well, however - they are favored by Greeks, Turks, Armenians, Jewish Klezmer musicians, and even some New Orleans Jazz traditionalists trying to get 'that sound'. I get requests on a monthly basis and sell quite a few to customers worldwide... who are relieved that they don't have to spend E2500+ for one from Markneukirchen!
For the record, many of the notes and fingerings are the same and switching wouldn't present much challenge to the educated player, as long as s/he had big hands - the spacing of keys is a bit wider than Boehm...and Albert does have its advantages! Partly in expressiveness (certain slurs and decorations are easier with fewer keys), and partly in its tone.
Ironically, in the effort to make the Boehm instrument more perfectly in tune, louder, more focused (all the qualities that Buffet's R13 is famous for), the tone has become thinner, blander, less rich and subtle. For a classical section player, this may be ideal. For a Greek or Trad Jazz musician, its contraindicated! Alberts sound great, as a listen to YouTube videos by older jazz and folk musicians will illustrate. Personally, I'm glad it has hung around all this time and hope the wave of revivalism in modern music will assure its continued use...