It's a shame that the 8/X isn't getting a proper feature update, but you should still be fine in terms of security updates. Apple released 12.5.7 earlier this year which is compatible with the 5S — a phone that's now ten years old. Apple has consistently provided security updates for it each year since its release.
serious question: what is your use case for 3.5mm in 2022? I am really happy with the wireless options available and couldn't imagine going back to cables. You have been missing out on great phones if lack of jack is a dealbreaker for you.
Loved my G5. A huge beast of a machine but a lovely design nonetheless. Would be great to revisit the beautiful case and build something more modern in it sometime.