Java tried to do fairly large updates and sometimes the release cycle would be very unpredictable as things would slip and take much longer than anticipated.
So to make it more predictable and to keep updates coming they switched to 6 months cadence with long term support (LTS) every two years.
This I think is a pretty good way of doing things, makes people who plan things figure out how to split feature development into these 6 months cycles, it made JEPs more granular and I think it made project Valhalla possible, if they tried doing it the old way it would never happen.
Splitting things in small chunks clarified what needs to be done and the path forward. It still takes very long time, but doesn't cause big incompatible changes and I think overall Java has good progress without being stalled.