Apple doesn't want to participate in such markets. That's why they try to push creativity narrative, "what's a computer" and so on. iPad can only succeed as a premium enough product, and that requires software differentiation.
I mean, the normal (and I assume best selling) iPad is about 300, and will likely be supported for a lot longer than the Android one (my Air 2 is getting on for 6 years old).
The problem with the cheap Android tablet is that unless the entire world standardises on a single model of tablet for these purposes you'd have all kinds of quirks around hardware, etc. Updates are also another issue even on premium-priced Android devices, so the cheap one is a lost cause.
The distinction here is Appliance vs Computing Platform. And so far many tablets are seen as appliances, not computers.
On Android you'd sadly find the lack of kernel compatibility with the chipset means that ever happens.
All one has to do is leave them connected to power and WiFi overnight.
It's more likely that the typical cafe checkout iPad is silently updated on a regular basis, after close of business, and the staff don't notice at all; since they're going to be password protected, they just punch in in the morning, as usual.
[edit] and you also need to have someone whose aware of those options to begin with which is less common outside prigramming enthusiasts imho. Because Apple has amazing marketing discovering an iPad solution is easy.
But when those other markets don't really take the bait, at some point it might be a good idea to accept that there is a market, but in a somewhat different place than originally anticipated.