@js I can manage plain unadorned Android 7 on a cheap Lenovo tablet. My youngest sister still uses a Nokia Lumia 1020 running Windows Phone 8·1 and its battery is just about useless, only lasting an hour before needing a charge. She just needs a basic phone & it’s looking like she’ll get a new Nokia 6.1, which is an Android One phone. This means it will get the latest “pure” versions of Android as soon as it becomes available.
She’s a technological minimalist, so I’ll have to help her to set up any new phone/tablet she would happen to get.