A bit off-topic, but the improvement/innovation distinction is another view I am rather sceptical about. If you zoom in on the 'improvements', you usually see the same picture again: Some of the improvements are seen as radical changes in the field itself, some still look as gradual improvements. Zoom in on the gradual improvements, same picture: what looks as gradual improvement from the outside, is unexpected innovation closer up.

I would argue it's innovation all the way through. Some improvements change a subfield, and from the outside it looks as gradual, expected improvement. Some change a field, and the outside world can notice it and say it's something fundamentally different.