The results... don't support that conclusion, actually. Looking over the history of the franchise since the original games, yes release dates have quickened overall.
so your argument is bad because you don't realize how significantly different 3 years in the 90s and 2000s was for game development compared to 2023
in the 90s and 2000s ATLUS, smaller JRPG company, could reliably essentially yearly release an entire JRPG
and then it took SMTV 4 years from reveal and it still ran at like 20FPS
3 years ain't SHIT in 3D game development.
Contrary to your other point, SWSH had a much larger dev team than Gens 4 or 5 or whatever. In fact, SWSH had 200 internal staff and 800 external contracted workers.
That's a lot of people, but not enough time for a 2.5ish year dev time.
Because remember, a lot of dev time goes to shipping and pre-production, aka planning. There is even less time than you think.
Pre 7th Gen Era, it was a lot easier to continuously shit out JRPGs, which is why almost half of most famous JRPG series' major entries are from before 2007.
I mean, look at Final Fantasy. Like 80% of all Shin Megami Tensei games are Pre 7th Gen, and Dragon Quest slowed down too. Pokemon is actually insane for not slowing down at all.
Before the Switch this could work because of simple facts of production. Worse power level to work with, less needed to make it look good for the system. Gen 7 was pretty polished for the 3DS. Then you transfer those graphics to a bigger screen, and even rendered at 4K it just doesn't look that good.
The screen real estate is bigger. The textures actually matter much more now. You have to put much more effort into keeping the immersion for the player.
But we have the same exact time frame.
And no, please god no not "hire more devs". Pokemon doesn't need more devs it needs more time.
Lastly: Don't trust Game Freak producers with their time frames because, according to them, development for SWSH started when they went to vacation in the UK and drew a British Pokemon Center.
That design never made it to the official game. And also the game only started real work after Sun and Moon was done.