The lie-flat business class seats aren't actually for those sorts of people, they are for ordinary corporate mid-level employees who fly for business. I have some Googler friends in Australia who will regularly take the bed-seats on the Sydney => SFO run. The company pays for it - when you're going to be paying the employee $10K anyway for the two weeks they're away, and they're generating well over that in value by having the next 3 months of work synced up with what the home office is doing, why would you not?
Even at making 10K per hour ($20M per year) its going to get quite pricey to fly a long range private jet.
https://www.aopa.org/news-and-media/all-news/2015/november/1...
It's the business travelers that are subsidizing the economy ones, not the other way round.
So it doesn't make sense to make economy more comfortable, actually the opposite.
The travel group I work for caters for corporations and luxury travelers, and they'd stop selling economy in a heartbeat if they could (it's a money-loser for the company, as there's little to no commissions on them)
That said, I would love to see an all business Airbus A321neoLR with Thompson Vantage Solo seats.
Who would want to have to put up with all those plebes?
Very rich people spend money to avoid ever waiting for anything or anyone who isn’t a close acquaintance or high status person. This is what private planes optimize for.