Asahi only really supports M1 and M2 macs, only even for them it's not 100% support. Though I guess it's comparable to how postmarketos / Ubuntu touch and other such Linux OSes work on Android devices.

i think there are some jailbreaks for the iphone and not the ios but a similar problem since they will stop being manifactured eventually.

Really hard not impossible. Even then we're decades away from even starting anything like that. Last jailbreak for ios was in ios 17 i believe? iOS is at 26 rn it did switch from 18 to 26 tho. Apple literally hired all the jailbreak devs to patch the exploits. There aren't even exploits that would help you personalize the phone and have better privacy since ios 18 and maybe a bit of early versions of 26. That's why I changed my phone when I messed up my password and had to update it.

Also the android on early iphones doesn't even work fully, it's a start yes but yea. And apple just also killed hackingtosh (mac in non apple machines) when they stopped to support intel. They could reverse ingenier the arm chip or whatevs, asahi has already done some reverse engeniering in the Apple m1 chip.

I don't think you have to jailbreak mac? idk i've never used one. So ye if we were to get custom stuff for ios it would take a lot years to even get a jailbreak and more years to get anything else and for that point almost anyone would be using that version of ios since you can't "downgrade".