Stretch your legs, go to any one of the several bathrooms at any time, hang out in the pantry car and even get a proper meal. Store all the luggage you want. Arrive just 20 minutes before the departure and still have time to laze around. Board/deboard in the center of the city rather than 40kms in the outskirts.

The benefits of rail over air are absolutely endless. And I haven't even mentioned the lower carbon footprint of electric rail (you can make electricity from renewable sources. Can't make jet fuel).