A common, shallow, cynical take…no, wait, never mind: it’s correct!
OS X has always supported multiple user accounts and I can’t see that ever changing.
The I-devices on the other hand are explicitly positioned as personal devices. And I don’t really see that changing either.
Nowadays the price of macs has dropped to the point where some of the iPads and phones (!) are more expensive than the cheapest (and perfectly capable) macs (I do my development on a baseline MacBook Air because it’s so conveniently light). So they are still selling (relatively) low cost, multiuser machines.
So, crystal-ball-gazing time: I don't think this part is true for iPadOS, but it's going to take them a couple more years to really get it right.
Here's where I think they're skating: watches and phones are personal devices, Macs remain what they are (personal computers, I could define this but it doesn't seem necessary on HN), and iPads (and HomePods) are family devices.
"Modes" and Family Sharing are both brand-new, and I can see effort to merge the two concepts so that you can put the family iPad in "Alice mode" or "Bob mode". Instead of separate user accounts (in MacOS each user sees a personal set of applications, that will never happen on i-anything), iCloud just manages all the login stuff in the background so that each user sees the subset of the system they're allowed, with their personal data and user accounts swapped out transparently.
This is a bad fit for how apps and logins work... right now. But Apple is clearly trying to fix that, like I said, I think this will take a couple years at minimum before we actually see it.
- iGadgets (phones, tablets, headsets, watches): will remain per-person
- "shared" devices (appletv, homepod, carplay, home iot devices) will take their settings from the per-person devices and will allow multiple per-person devices simultaneously. So the speaker will play songs / respond to requests from people whose phones are on the LAN; the car will take its default settings from the driver (how will it know?) but the passenger can control the map etc.
