I have an iPhone 15. I am NOT being offered the 18.7.3 and only the iOS 26.2.
I have seen many site pages saying that if your device is incompatible of using iOS 26 then you will get offers for various iOS 18 updates. Obviously your older model 12 is on that list. So, let’s tell the truth. The Mac poobahs have decided that capable means necessary or mandatory. 12 is not but 15 is. The 13 and 14 models I don’t know, so you will have to check but I am stuck at 18.6.2 unless I go for 26.2.
BTW: I am not being allowed any Beta options on my phone and I have looked everywhere for Beta update options.
So why not jump to 26?
A: can’t go back.
B: reports of this version being so different it’s like going to Linux (not a bad thing but not what I want on a phone).
C: you loose all or many settings you spent HOURS getting right.
D: many apps not working nearly as well as they did before (after you spent hours fine tuning them).