This is nice, apart from a quick play when they were new I've never really looked at CF Workers and KV again. This made me go and have a look at the docs and find that it's actually looks quite useful. I didn't know they'd added Python and other languages, so that's cool in itself. I like Jon's example here, a single and fairly short file that does just enough to demo this all, nice.
I'm building a blog directory/reader/search engine [1] on Cloudflare Workers with D1 as the main database. Very pleased with the ecosystem, including Queues and scheduled jobs. DB migrations are simple, local development is a breeze (scheduled jobs don't work though, but there's a simple workaround), and the DB is an SQLite implementation. I am worried about vendor lock in, but as long as I keep the app relatively straight-forward, it shouldn't be a huge deal to migrate to some other Node or Deno backend.