exactly so, yet there appear to be people investing large fortunes, presumably in the hope of getting an even larger fortune back. There's no sign of anyone wanting to start small and build up over the course of decades, like Embraer.
Best way to make a small fortune building commercial jetliners is to start with a large fortune...
I'm just wondering if advances in technology mean it's suddenly feasible for beginners to push bounds of aviation.
If anything, it's made it harder. For all the flack the FAA has gotten over the MAX fiasco, it's far harder to certify something now that it was even 30 years ago (and an order of magnitude harder than it was 50 years ago. As just one example, for the 747-400, the certification plan for the FADEC engine control system was about 30 pages long - that for 3 engine types (CF6-80C2, PW4000, and RB211-524) and two aircraft types (747 and 767). As just one example, 25 years later, my engine control cert plan for the 767-2C/KC-46 (one engine type - PW4000 - no hardware changes, new software only with one 'new' function) was over 100 pages long (I know because I was able to locate the original cert plan to use as a reference while creating the 767-2C cert plan).
Boeing managed to build and certify the 747SP and make some money only producing 45 of them. Now day's you'd need to produce at least 100 to just break even on the non-recurring costs of design and cert.