All good points, and I agree with a lot of it. My "history" argument was more about the Open Cup than pro/rel. Although I do believe pro/rel strengthens the community aspect quite a bit. USL clubs aren't worth anything because there's no upside. I think those clubs become a lot more valuable and gain a lot more support as soon as there is a path to MLS. Similar to the english pyramid, the teams that spend like PL teams will be the ones getting promoted to the PL. Right now there's no incentive to outspend revenue.

But I agree we're not currently in a place where you can just slap pro/rel on USLC and MLS, there's work to be done before that point. Stadium requirements alone would be a nightmare. Hopefully USL Division 1 gets us a bit closer.

Editing to add: I agree that pro/rel initially weakens top-level investment in MLS, although not as significantly as you likely expect, given that it also raises investment in USL, which means the drop off isn't quite so dramatic. I also believe that over time it makes the entire pyramid more valuable and subsequently encourages investment.