Point is well taken. I have not tried cloudflare workers yet. It seemed like at least the architecture was the same. But I guess you would not have access to the full browser API. It seems like you can still play around with request / response side of things though.
Cloudflare Workers is so-named because it uses the same API as Service Workers, which are one kind of Web Worker. That said, Cloudflare Workers currently implements only a subset of the APIs that are normally available in the browser, though missing APIs are being added all the time.