iPadOS 16 was at least updated 3 months ago (August) so there's a chance you could still get a security update if it's applicable to that version. iPadOS 15 was updated in July.

https://en.wikipedia.org/wiki/IPadOS_version_history

That wasn't an actual security update; that only fixed a broken toggle switch for "Advanced Data Protection" in Settings. I'm talking about patches for vulnerabilities.

iPadOS 15 hasn't been receiving the security updates for vulnerabilities that have been released for iPadOS 18.

It's hard to keep selling you new iPads every year if they did that. They might have to replace the dollar bill dispensers with ordinary toilet roll in the Apple washrooms.

(Meta: hard to not notice every comment in this thread critical of sacred cow Apple is being mass downvoted as per usual.)

It's probably because the first bit isn't really true (iPads have a longer supported life than many Android tablets, for example I updated my 2018 iPad Pro with the most recent iPadOS 18.1.1 including this security fix earlier today). And given that the silly joke falls flat.

The iPad 5 in question from the OP supports iPadOS 16 and that last got a security update in August of this year. So if it hasn't got an update today then possibly the vulnerability was only introduced in iOS / iPadOS 17.

Meta meta: comments making vague complaints about other comments being downvoted, typically get downvoted.

I can assure you that the toilet paper is much more comfortable than dollar bills.

Apple really cares about saving the planet so they will graciously allow you to recycle your working iPad and buy a new one.