The core issue here, and Pantheon being a prime example of it: Making an MMO is a complex task, and you can't let the amateur hour run the show.
Yes, the tools have become simpler, especially the ones shared with single-player and match-based multiplayer games, but the most important part is the database layer, and all the anti-cheat stuff. Because if the players don't have any trust in your product, they sure as hell aren't investing a thousand hours into it.
There are interesting new developments like SpacetimeDB that seemingly make things easier, but they are not proven, and I can see some issues with their approach.