10Base2 was going out 20 years ago, not coming in. I was working with it over 30 years ago and it wasn't new then.About 20 years ago I worked on an early industrial computer control system which was networked with 50 Ohm coax.
21 years ago we put in both co-ax and twisted pair for our then new network and never used the co-ax. I cut it all out and binned it at least 15 years ago.
For some strange reason I've still got an ethernet transceiver (again brand new; for the thick yellow cable - the stuff before 10base2) and some BNC T-pieces and terminators.