Let me be the first to tell you, I feel you and agree... and as @logfiles
impressively summed up those threads this has been discussed before. And IIRC it's something I've discussed with theymos long time ago as well.
From memory and current opinion here is why is stayed the same for all this time:
- Removing obsolete profile fields would mess up whatever data is stored in them.
- Adding new ones without removing obselete fields just clutters the profile page.
- Low priority, as there are alternatives like repurposing existing fields, signature space, etc.
I'd like for this and other things to improve and throughout the years I've probably nagged theymos with suggestions more than just about anyone

And some of them did eventually get implemented. Be it new sections or other suggestions for patches like the ones @PowerGlove did.
In general, if we identify something that needs improving and come up with a
solution plus some code to back it up I'm fairly convinced theymos would at least consider implementing it!
[1] I'm 99% sure that the 2FA/TOTP patch will get merged. And I'm
100% sure that I'll open a bottle of something special when it does.

Then allow me to be the first to raise the glass when it happens!
On-topic: Yep, the profile page/settings could use some attention. I've got some ideas about how to migrate those fixed-label messenger links to something more free-form, but I haven't thought about it deeply. I'll read through the topics logfiles posted, and see what folks have said/suggested in the past.
Now we're getting somewhere...
What about something like this:
- The number of fields, platform names and user input remains the same. This is how existing information is preserved.
- In the
Forum Profile Information page a dropdown menu is added next to the defaults to switch with some new ones (Discord, Telegram, etc). This also keeps the same number of contact fields.
- Updating the contact fields should also update the small logo under the user's avatar, displayed in posts.
PS: Thanks again @PowerGlove for your efforts!