Hauling drinks aren’t as expensive so no need to up-sell the service, just give me a snack station.
One row of 6 business class seats replaces what, 20-30 eco seats? That‘s where the cost comes from. So they need to be a factor of 3-5 more expensive because of space with everything else equal.
The point is just that you want "office class" on a train to be its own product. If I take a high speed train I am still probably just going to go and do some more work from a hotel, office or home.
So just make the slower train nice enough instead and save on the expensive track upgrades. Just don't try to sell me, or include, a 3€ water or a 25€ meal because then the extra time becomes a liability and you ruin the concept.