I think Rails is a victim of its own success: many of the hot new Rails codebases from that time are now 10 year old monoliths. And those monoliths need incredible amounts of tests to compensate for the lack of compile-time type checking, Rails version upgrades are multi-month nightmares, and the object-oriented statefulness of the language means that complex load-bearing code can be extremely tricky to untangle.
There are certainly new compelling projects like Sorbet to add type checking, and the ecosystem itself is very mature, it's just that the average codebase is not going to live up the experience you might have with a brand new one.
There are certainly new compelling projects like Sorbet to add type checking, and the ecosystem itself is very mature, it's just that the average codebase is not going to live up the experience you might have with a brand new one.