How much better or worse will Switch 2's 3rd Party Support be?

[Louie]

A lot better. Microsoft is basically going third party right now and Sony has more or less given up on Japan. Most games released today still run on PS4, Xbox One and Series S, Steam Deck... so Switch 2 will be able to play all these games. If publishers are clever, they will release their games on Switch 2. There is simply no reason not to release titles on the console.

If third party Switch 2 games look good enough Switch 2 will be by far the most attractive dedicated gaming platform on the planet, as it'll be the only platform with a large number of actual exclusive titles.