That's a rather unrealistic expectation.
Not every gamer can afford a ps5 or will purchase one. The ps5 sales in Japan for example are quite bad, only 3 million ps5s have been sold until now...
The ps5 install base is around 30 million currently, even if we go with optimistic forecasts of 25 million for the fiscal year that would be 55 million. You really think ignoring an install base more than 2x the ps5s for a console that has no presence in the region where one third of personas total sales originate is a smart idea for the firm?
GTFOH with this narrative. PS5 is outpacing PS4 and PS3 sales in Japan; those aren't Switch numbers but Switch has the advantage of being (basically) a portable, I would say in Japan the vast majority use it as a handheld rather than a home console. PS5 sales could be better but they aren't "quite bad"; that would fit Xbox sales much better and that is being generous.
Also the late note from the previous investor call was ~ 36 million, not 30 million. 30 million comes from the start of the year. What's funny (well, kind of) is that by your example, SMT5 should have sold much better than it did, given the Switch's install base in Japan at the time, but it just goes to show you that install base is not a direct correlator to actual software sales. A game isn't going to increase its sales by 2x on Platform B over Platform A just because Platform B has 2x an install base over Platform A. There's a lot more involved, technically speaking.
You even end up contradicting yourself anyway: if the other Persona games have been on a platform that's doing (or in case of PS4, done) "quite bad", yet 1/3 of all Persona sales are coming from the region where the games have mostly been exclusive to that badly performing platform (for at least many years timed), then that kind of squashes the idea said platform is doing "quite badly" in that region, no? Again, yeah the sales could improve, it'd be nice to see PS5 start tracking near PS2 levels in Japan but realistically that's probably not going to happen unless they also make a handheld and count the two as part of the same device family. We'll see what that rumored Q-Lite turns out to be in that regard.
And software sales could maybe be better too, though Famitsu nor Media Create track digital, and on the Switch 3P software is generally doing mediocre at best even in Japan (but no one wants to talk about that). But PS5 hardware itself? It's doing better than PS4 was, I wouldn't call that 'quite bad'.