>So many things that used to work without a smartphone don’t anymore and people don’t realize it.

Have you considered using a GNU/Linux phone (Librem 5 or Pinephone)? There is no dependence on a megacorp and QR codes work fine. Some services might redirect you to a web app if you show them such phone.

A committed Windows user who just noted they depend on iMessages probably isn't a great prospect for your proselytizing, anyway: https://news.ycombinator.com/item?id=38855086

I've previously tried living out of a PinePhone Pro, and if those web apps require much JS at all they're going to be in for a bad time. By benchmarks and your previous accounts, it sounds like the Librem 5 is only going to be worse from there.

But you nod towards a useful point there at the end. I've found I don't need to present ancient hardware to get some entities to provide web apps or other means, I just say something handwavy about my phone being locked down by my employer's IT policy, neglecting to mention that I'm my employer. Bigger orgs aren't worth bothering with, though. You could show an airline an employee a flip phone and they aren't going to have any flexibility on the matter.