OP is heading in the right track but hasn't come to the ultimate conclusion yet: PS4 and Switch are in different generations.
This makes them different for all sorts of reasons. For example PS4 has multiple versions while Switch only has 1. That is because Switch is a lot younger than PS4. Switch will have multiple versions eventually too. But Switch is young and still growing. PS4 is old and ready to have a successor. They are in two different generations.