Very similar situation. I have been cancelled, and I can't face going back to employment, but finding a way to earn a crust as a solo engineer is proving somewhat hopeless. At least I'm not paying tax any more. Checkmate Rachel Reeves.
It's true that (these days) typically, a senior dev will be handy with AWS. It's certainly not true that a senior dev is defined by being good with AWS. I bet Linus Torvalds isn't a big AWS guy.
I share your scepticism of the cloud, particularly AWS. They create this hugely complex system, charge the earth, and then rather than bend over backwards to help people learn, they have the audacity to charge more money for the training and certifications.
Rather than set up your own physical infra, I think it's reasonable to pay for a VPS. To me that's not 'the cloud'. Get a barebones linux environment, and you can do whatever you like.
My whole mantra is making fast and lightweight apps. Being able to create apps and services without needing the cloud, I think, is an equally valid characteristic that you might expect a senior dev to have.
This is cool. I'm actually working on a trivial web-app that will be similar. I'm just doing it as an exercise before I undertake something a bit more ambitious, but I'll be drawing inspiration from yours.