I have had my own phone line and phone number since I was a teenager in the early 1990's, when my parents gave in to my wish to have a line to connect my computer to and run a BBS on.
At that time I was a member of Fidonet (2:230/149) and AmiNet, and at some point I started to get email and usenet news via a gateway in Sweden. That was expensive. The first phone bill after I started polling the gateway was when we decided that I should pay my own bill.
Tomorrow I'm changing to a different ISP, after the one I had been a customer of for 10+ years has been swallowed by the largest such corporate entity in Denmark, with the expected worsening of the conditions that entailed.
The old ISP offered a SIP-based way to keep the old phone number, so in that way I kept my 1990's phone number. The new ISP doesn't offer that service, so I'm giving up my "land line" and accompanying phone number.
I've only held on to it for nostalgic reasons - I had a tape-based answering machine connected, and by now the only ones calling it are "Microsoft" from India, trying to convince me that my computer is broken.
Still, it is an end, letting go of that phone number.