True, but usually you buy them from retailers... This way they cut out the middleman. And the chance that you use 3rd party inks (although, that "security risk" got patched with firmware upgrades)

Also, they don't just send you ink... It's a monthly plan where you have x pages included. Unused pages are rolled over 3 times [1] and afterwards they probably are just lost.

Further, if you cancel the subscription, containers you received within the subscription wont work anymore.

Damn, I knew it was bad, but now that I read the details it's even worse...

[1] https://www.hp.com/us-en/shop/cv/instantink