I really like it went this bad as always, because apparently as disclosed at Google IO 2018 they are finally considering making updates a requirement on the license agreements.
Where could one find graphs of the Android major versions' distribution percentage over time? https://developer.android.com/about/dashboards/ just shows today's numbers. I'd like to see a "distribution vs days since following version released" with a line for each old version.
Needs an update though; this one only goes up to February this year.
If anything, Oreo would see lower uptake due to Treble, although that's mitigated by not making Treble a requirement for Oreo upgrades (ie. even if your device was upgraded to Oreo from something < 8.0, Treble still won't help you)
USA, EU, etc. are more than 40%.