They're smart about this. It's infrastructure lock-in but not at the API/application level, as they are trying to stay as close to "just JavaScript with browser API semantics" as possible. Deno is a project that does this too. If you know service workers and web workers you know Cloudflare Workers. If you know JS OO you know Durable Objects (to a degree).

Think about it, the huge influx of web developers that have been growing up on just using JS. Look at their docs too. It's all very accessible, modern, low friction stuff all while they are selling us their infrastructure. And they communicate in a technical, programmer friendly way as opposed to the business/marketing jargon that we are used to by some of the others.