Nintendo has been doing incredible, especially considering what their output has looked like. It isn't bad by any means, good even, but there's several cases where you wonder what's up.
Nintendo focuses on varied game projects with a generally smaller production scale than what SIE aims for, thus leading to Nintendo releasing a lot more titles by comparison: Mario of various kinds, Zelda, Kirby, Metroid, Splatoon, Fire Emblem, Pikmin, Animal Crossing, Xenoblade, Arms, Smash Bros, Ring Fit Adventure, alongside of Famicom Detective Club and other collaboration projects (Bayonetta, Another Code, Astral Chain, Buddy Mission Bond).
Nintendo also has multiple internal development teams where members can be relocated to other projects when needed, I recall this was the case for instance with the TotK team helping out Monolith Soft for Xenoblade 3.
Meanwhile, Team Asobi had 35 people in 2021 and which later grew to 60 in 2022. But Japan Studio was made out of over 200 people and most of the former talent were either hired by Nintendo/Monolith Soft or went on creating their own studio. Nevermind that Japan Studio also acted as a vital business bridge between Sony and Japanese third-parties for collaborated projects.
They definitely got better 3rd party support than they had with either the Wii, or Wii U, but it's well below their NES & SNES hayday. I'd say it's been about on par with GC, at least in terms of notable exclusives.
The most impressive thing remains Nintendo absorbed the third-party support that was a lot more synonymous with the Playstation brand in prior generations. Hence why I sometimes jokingly call the console a Playstation Switch (and one main reason it became my current main platform for vidya).
This turn of events obviously didn't happen overnight back when the Switch started but it evolved slowly and progressively across the last seven years. And it's more or less expected to see the franchises/titles missing on the current Nintendo hardware (such as From Software, Ryu ga Gotoku, Granblue Fantasy, EDF5 & 6 for example) to finally appear on the successor.
And unlike SIE, Nintendo doesn't depend on third-parties as an essential part of its success thanks to the large gallery of its own active IPs.