Amazon is a company motivated by profit. No one at the company is going to throw money at a problem unless solving it will be profitable. New World standard edition is $39.99, with no subscription fee. Blizzard used to charge a small fee to buy the game, but the monthly sub cost was what sustained it. They recently dropped the up-front cost. Users pay per month and play, and there are plenty of additional premium things to buy, fortunately they are all aesthetic, compared to many free-to-play that end up being pay-to-win.
It's unclear how Amazon will make money on New World, although I strongly suspect it will involve collecting and selling data about the users, along with some kind of microtransactions. I'd guess freemiums will come along later, too.
In short, just having a lot of money is not sufficient. For a business to want to solve the MMO scaling problems, it has to find a way to get some return on the investment. MMOs just aren't All That.
Thank you for taking the time to write that out.
I'm sure all the issues you cite can be solved, but it costs money to address them. How much are you willing to pay to play an MMO, either up front, subscription, or free-to-play freemium?