dunno, there is the one-time toggle in the notification area for 100% in my pixel and there is a toggle to turn off these adaptive features in settings.
It is a feature you can easily turn off on iPhones too, it isn't hidden or obscured under bajillion menus at all. The grandparent comment just didn't bother looking for it.
Settings > Battery > Battery Health and Charging. Set "Optimize Battery Charging" toggle to off, and the adaptive charging is gone.
