[roger albert]

The GP and SBKs are a LONG ways from each other in technology, but not much in execution and power and times. 1000CCs of fairly high tech isn't far off of 800CCs of extremely high tech.
Most of the difference is down to a bit of electronics, the weight, and of course the riders.
When the GPs move back to 1000cc, and a bit more cost limitations, then those 3 things will be about it, period.

It's a diminishing returns thing. Look, in similar spec, 1000s aren't that much faster, laptime wise, than 600s. Close to 100% more displacement, and less than 5% faster.
Given that the MotoGP bikes and their tech have to overcome a 200cc displacement disadvantage, it's not surprising they're not much quicker. It takes a LOT of extra skill and technology to go even a bit faster, the moreso when spotting those 200cc