Until Ryzen forced Intel to get off their asses there was very little performance improvement generation by generation in intel processors.
For example: Over 2011 - 2017 there was a ~18% (userbenchmark) improvement in the *700 i7 model.
https://cpu.userbenchmark.com/Compare/Intel-Core-i7-2700K-vs...
But then Ryzen came out and the very next model (released in the same year) was already a ~23% improvement.
https://cpu.userbenchmark.com/Compare/Intel-Core-i7-7700-vs-...