https://issues.chromium.org/issues/40090179 is as sad as it is hilarious...

At some point Chrome OS implemented fashionable (but utterly unusable) overlay scroll bars, and it took 7 years of users complaining for the team to implement a setting to get the normal scroll bars back. Which was harder for them than you'd think for various technical reasons. And non-technical.

But here's the kicker: for the setting to do anything, you gotta go into chrome://flags#overlay-scrollbars and flip that flag first