If that were true, then these games would only land on the particular console they decided on. But most game studios develop in either UE5 or Unity and release for all consoles and PC, so what you say sounds wrong.
In fact the whole drama that is currently going on with PlayStation and XBox fans is about games being released into PC, given the stagnating growth of user base in their consoles.
Meanwhile Switch doesn't even care PC exists, other than for the devkit.
People mostly don't write custom game engines any more, so they don't care about platform specifics. And game studios care about sales, so it doesn't make any sense to not distribute on multiple platforms!
The reason why Xbox and PlayStation have games that only exist on their console is because they secure that contractually, and they pay a ton of money for that.
And Nintendo releases Mario and Zelda only on the Switch for that exact reason.