It is pretty obvious rails is dead as it hangs massively on its founder for good and for bad.
And it is quite telling that he prefers to kill it off like this rather than handing the reigns over to someone else.
A technical note - the big difference is that a design with a number of fat clients don’t need server side rendered html - that lowers the load on the server regardless of the programming language.
You can probably write quite light json apis in Ruby and the performance of them will be dominated by network and db usage anyways compared to a similar implementation done in a compiled language.
https://github.com/rails/rails/commits/main/
https://github.com/rails/rails/graphs/contributors?from=6%2F...
Zero commits are from DHH. It seems he already handed reigns over to other people.
Rails has died many deaths over the years. I suppose its ironic that yet another one will be at the hands of its creator, as part of the keynote of a Rails conference he created because the community tried to have one conference where he wasn't the focus of attention.
All this does is justify the people that have been trying to move on from DHH for years. If his politics didn't do it, or his bullying, maybe the fact that he doesn't even use Rails himself will pull the wool from their eyes.
Rails itself will continue. I see no reason to stop using it.