Current employees are experts at the code base and processes. They have way higher value for the company than other equally good in general non-employees, who would have to spend alot of payed time to get into things.
But also processes -- a big one if you're in a large org -- subject matter, even simple stuff like getting a laptop setup and getting AD groups set up correctly for all roles and accesses can take a long time. I've been at multiple multinationals/F500s and it often took 3 months just to get me into things (part of that also being we don't give sudo/admin to the newly hired).
I've known PMs from aviation work that aren't deeply technical but know TONS about how to drive projects in that sector, who to contact, what's a priority, and that's not something you can easily put into a udemy course the way you can SAP or NodeJS.
This is probably more appropriately said as "don't know". To give a past example, Final Fantasy 7 was pretty famous for having bad character models but it didn't take long for the same team to figure out how to make better ones. FF8 had much more real-looking models. Not many games today look significantly better than FF15 on standard console hardware.
Probably the "disaster" in the Pokemon game context is that Nintendo didn't feel the need to keep up rather than that they couldn't keep up. I get the feeling that the generation 10 games are going to be a strong counter statement to such comments. Likely in no small part because the people working on it are the same people who released the games which critics like to call a disaster.
Nintendo is the publisher of the Pokemon games and co-owner of the Pokemon IP. However, they do NOT develop the Pokemon games - that's Game Freak.