HEY! Watch it! I’m still running copper here with POTS and DSL over it. It just works. I had ISDN before DSL with two bonded B channels for 128 kbps way before DSL, too. The costs were horrendous with two simultaneous metered calls to a nearby exchange.
I went through the same process, but opted for just 1 B channel until the DSL over a dedicated pair was offered. A couple years later, the first DSL that could operate on top of a voice line was introduced. I still have my 1996 vintage ISDN terminal adapter in a box.