>So - while I would prefer a "monitored solution" to border control over physical imposing measures, my real preference would be for us to all work toward eliminating these national-level borders completely.
You sound like someone with the ability to live anywhere, who consequently has little stake in their current "somewhere." Lots of Americans (and people in other countries) don't have this flexibility. They are directly and inescapably effected by the de facto U.S. open border policy for low-skilled workers. For example:
I have family in New England who ran an all-organic dairy farm. They had to shut down a few years ago, in part because they couldn't compete with the farms who paid undocumented workers under the table. At the same time, their rural community has been decimated by the opioid crisis. Most fentanyl in the U.S. comes in via the unsecured border with Mexico [0].
We've seen what happens when other countries adopt wholesale open borders policies. In Germany, the 2015 migrant crisis nearly brought the far-right "Alternativ für Deutschland" into power. That crisis only abated once the Balkan states took it upon themselves to secure the E.U.'s southern border.
Finally, I also think it's likely that any compromise to solve the border crises will involve additional border security measure. We've come close enough before to know what such a bill might look like - remember when George W. Bush strongly supported the DREAM Act, amnesty, and a path to citizenship? [1]. Why not develop the necessary technology now?
[0] https://www.latimes.com/world/mexico-americas/la-fg-mexico-d...
[1] https://en.wikipedia.org/wiki/Comprehensive_Immigration_Refo...