It's not just Capcom, From Soft was one of the devs advertised as developing games for Switch, IIRC this was early 2017.
Atlus hasn't been doing much either. We haven't really gotten anything new from them outside of announcements for announcements of SMTV.
Basically, the kinds of games you'd expect on 3DS and Vita have been very slow in appearing on the Switch, if at all.
I don't know if you can treat all devs as the same issue or even that this is the same level of support we had with 3DS cause in some of the cases you mentioned above it was better before.
In general it's true that at launch many of them weren't confident in the success of the system due to the failure of Wii U so many preferred to wait and see, but now there is no point discussing that anymore, Switch is a huge success and already has a very big installed base for an almost 3 years old console. Those who had real plans to support the system like for instance Square Enix or Marvelous, have started to bring a lot of new games including exclusives.
From Software -> one of those you should have never expected much: they've never been on Nintendo systems before, they don't rely on those sales. I was expecting Dark Souls trilogy to be on Switch by now, it's possible that was originally the plan but as you may know, Bandai Namco fucked up the remaster of the first game so badly that it sold poorly on all systems.
Atlus -> They started working late with the Switch hardware by their own admission. With 3DS they were developing games even before launch, with Switch they started full scale production of SMTV in 2018, a year after the announcement.
But i think this also reflects the weird state of the company. They want to work on Persona as much as possible and probably don't put enough time on their other projects they'd maybe like to destroy but the old veteran developers there still fight for those.
My conspiracy theory is that they wanted to bring Persona 5 on Switch especially after all the love and free marketing Sakurai has done for them, but couldn't because mainline is Sony exclusive so they worked with Koei Tecmo (who is very experienced with the hardware) on Scramble which they literally call it P5 2 on trailers and keep repeating that this is a direct sequel and not just a spin-off.
You'll see SMTV and Etrian Odyssey on Switch but it's gonna take time. After V you may see new SMT spin-offs (since they worked on these new assets and Atlus usually tends to recycle) but don't expect too much cause Atlus is more and more just Persona focused.
Capcom -> I think something happened between them and Nintendo.
We knew they were planning a new strategy to reach global success, but to go from Monster Hunter, Resident Evil spin-offs, and Ace Attorney all Nintendo exclusives to no exclusives anymore, and not even getting their biggest games, that's a big shift.
You may argue with their new strategy they may have stopped with exclusives in general, but that's not true cause they still keep doing those with Sony.
My idea is that they never really planned anything for Switch, with Atlus they did plan stuff but started late, here there truly is nothing, that's why they had to port all those old games to make it look like they are supporting but If you look at their actual catalogue on Switch, you'll see those are very very old remasters, fairly easy and cheap to port. It's nowhere near as comparable as investing in new titles designed for the system.