Games which are 10 hours or Animal Crossing Bells less are perfect. I will happily spend $60 on a 8-10 hour game that's concise and does not waste my time.
There's a couple of twitter accounts/subreddits you may follow to get upgrades on PS5 restocks! You may already know about them but I guess it's worth throwing out there in case you don't - that's how I got mine
You are correct though, the change is currently very much a thing that's just good on occasion. In a ideal world Nintendo would be investing in new party content to where they're falling a brand new game (or even a interface as long as it's not $60) every couple months but. . That doesn't occur. Even a gamecube library like you mentioned would knock my socks off.
On Twitter I turned on notifications for Nook Miles Ticket For Sale @Wario64 and @PS5Stockalerts which got me close a few of times but that I had no chance, although others got it for sure.