I don't think I'm side-stepping the issue with exchanges facilitating so many payments, mainly because I can easily rationalize that individuals still have the ability to very easily send payments on-chain to one another with or without an exchange. That is not the case with lightning.

I wouldn't frame my pov as "lightning is more of a failure than bitcoin" or that custodial bitcoin MoE would be equal to failing. I do, however, believe that the direction lightning is headed in as a primarily custodial layer for bitcoin payments undercuts most of what makes bitcoin so powerful as a peer-to-peer network. My fear is that if lightning continues in this direction it will be as unimpressive as USDC or Tether.

Framing this more broadly: What incentive do people have to acquire and then spend bitcoin if it works just like fiat does? It's cheaper and more convenient to spend in dollars or USDC in most situations today. The ideal of lightning (self-hosted, instant, peer-to-peer) is inspiring. But the reality is so far from that ideal and I think the compromises have gone too far for too long.