Another question: Is there anyone here who operates as a sport pilot? If so, what was your reasoning for stopping there, not including "lacka funda.."
Well, not a 100% answer to your question, but I operated as a SP for a while. Got my SP ticket in 2017, PP in 2019. Had MOSAIC existed at the time, I probably would have stopped at SP, but I wanted a more capable aircraft, one that had plenty of luggage space and better handling in windy conditions.
To get my SI medical required significant expense for tests, medical records, and letters from several doctors, plus a flight to Illinois to visit Bruce. Submitting 400 pages of records + 3 months waiting got me a class 3, and I immediately went to Basic Med.
None of that crap made me any healthier than I was as a SP, so the class 3 did not in any way change the likelihood of medical incapacitation.
If MOSAIC had existed back in 2019, I very likely would have stopped at SP, and my reasoning would have been "It's all I need for the type of flying I intend to do."
MOSAIC
might increase the number of SPs, but I suspect it won't make much impact on the total number of new pilots. Rather, some students will stop at SP who previously would have continued to PP, because they will consider SP to be sufficient. It's a guess, but I imagine many of those will be older students, people approaching retirement or already retired, whose kids are grown, mortgage paid off, etc., and who might have some hassle getting a medical. Such students won't be looking for a new career, and instead will just be looking for a fun hobby and to load up spouse and luggage for an occasional trip. SP plus a 172 or Cherokee (or even an older Bo) might be just the ticket.