The difference here is that 3,5mm jacks are not obsolete.
Nobody besides a few grumpy folks opposed the switch from microUSB to Type-C, for example, because we got something better instead.
Floppy drives got obsolete, because again, we got something better - disks! And then flash drives! Always a better, more convenient and functional option.
3,5 mm jack, however, is still completely relevant and is not replaced by anything. It is the only widely adopted consumer-grade standard for analog wired audio. Wireless audio has objective drawbacks: one more battery to control, lower reliability, poorer sound quality (not a big issue with most phones since their DACs are normally not audiophile-grade anyway, but still), higher price, pairing issues, and many more. And USB-C to 3,5mm dongles are obviously terrible: they can get lost, they don’t allow you to listen to music while charging your phone/transferring files, and they are yet another component to manage.
Essentially, wireless audio has been pushed down our throats, and we do not appreciate that. For me, not having a 3,5mm jack is one of the criterions that immediately kill any desire to buy that phone. It will just be a massive pain in the ass for me, and I don’t want that.
Mental Outlaw also has the great guide explaining the install step-by-step in a great detail