The MTR in HK heading to Lo Wu / Lok Ma Chau has a first class section: https://en.wikipedia.org/wiki/East_Rail_line

It doesn't increase public transportation use.

People in North America don't take public transit because: - it doesn't take them to where they need to go; - it doesn't take them to their destination timely relative to a car; and/or - it doesn't have frequent enough service to not get bored to death, baked into heat stroke, or frozen to death in -30C weather, on a Saturday early evening

"Business class" is just a lip stick on a pig.