It's more that progress has become more incremental, while most of the low-hanging fruit has already been picked (as in other disciplines). But progress has not

It's more that progress has become more incremental, while most of the low-hanging fruit has already been picked (as in other disciplines). But progress has not stopped. For example, contrast what the 1996 and 2011 editions of the Garbage Collection Handbook have to say on (hard) real-time garbage collection. Real-time GC has seen a lot of progress since 2000. And there have been also plenty of discoveries in other areas. For example, Monte-Carlo tree search, as used by Go-playing programs, is about a decade old [1]. [1] https://hal.inria.fr/inria-00116992/document https://hal.inria.fr/inria-00116992/document