Depends which class you travel, and with which airline. Even in economy, the "legacy" European carriers are generally more comfortable than a bus. The ability to pay more to make the travel bearable is an advantage of air travel.
> Also, let's not forget that the experience of traveling by bus got worse mostly because of the popularization of low-cost short-haul flights, and that has killed the market for "premium" bus traveling. If short-haul flights were out of the picture, I wouldn't be surprised if someone started offering bus travel with larger seats (in 2-1 configuration) and even more sleeper buses for night travels.
You're right that air travel has made premium buses moot, but I think that's a good thing. Spending 12+ hours on a bus is not an improvement over a 2 hour flight, even if you have a bed on the bus. You can spend the night in your own bed and then get to the destination at the same time, having slept better and with less risk of accidental injury. The emissions gap between the two modes is narrowing rapidly, too.
My argument is that there is no such thing as a 2-hour flight. We still need to factor the time to get to the airport, check-in/boarding, getting off the plane, waiting for luggage, and then getting from the airport to your actual destination. That easily transforms any trip into a 5- or 6-hour event.
Factor in that if you are flying to a place where you need a hotel to "sleep on your own bed", suddenly even a very luxurious night bus might come out ahead in price and practicality.
Granted, for an European context it makes a lot less sense to talk about intercity bus because we have a reasonably extensive rail network. But put your hate of buses aside for a moment and consider that buses can be better, so from a North American perspective it can make sense to consider it.
Also, let's not forget that the experience of traveling by bus got worse mostly because of the popularization of low-cost short-haul flights, and that has killed the market for "premium" bus traveling. If short-haul flights were out of the picture, I wouldn't be surprised if someone started offering bus travel with larger seats (in 2-1 configuration) and even more sleeper buses for night travels [0]
[0]: https://www.youtube.com/watch?v=WRTzEJ8znL0