With apologies to Obama, if you like Cloudflare you can keep your Cloudflare. It looks like celld is not intended to be an exact clone of Cloudflare but is for someone who wants to run a bunch of workers in a single region.
If it were intended to be a direct alternative for the biggest use case, I think it would be more like Cloudflare Workers and Durable Objects. However, I think it's an alternative for a lot of uses of those two things. For a lot of uses of them, likely most uses, they are overkill.
It's a 100% open play, despite mentioning three hosted APIs: S3, Cloudflare Workers, and Durable Objects. The thing is, that Deno tried making similar ones. Deno Deploy is analagous to S3, and Deno KV is analagous to Durable Objects. However, now the only dependencies are being able to run a binary and some S3-compatible storage.
FWIW here's an old Deno blog post comparing Durable Objects to other stuff: https://denoland.medium.com/deno-kv-vs-cloudflare-workers-kv...
Geo-sync? I'm pretty sure durable objects are tied to the datacenter they are created in.
nothing beats cloudflare's reach they have nodes everywhere
thats hard to beat
on the one hand, hosting is hard, you should pay people to host, especially distributed systems.
on the other hand, deno land folks stole from (used open source from) the best. the coordination layer/control-plane is all S3 CAS of dumb json files, which is a fantastic common-mode infra requirement for most orgs anyways, & perhaps a durable control-plane substrate you'd feel comfortable having someone else run (such as aws or others), while you run the data-plane (workers) yourself. and then for the durable objects themselves, they used litestream, which is a pretty top pick, excellent way to get radical distribution (but actual topology not included, some assembly required)! https://hn.algolia.com/?q=litestream
there's no reason this wouldn't run fine on most hosting, you definitely don't need bare metal. the virtues of v8 sandboxing / isolates! no need for vm's at all, no nested vm difficulties if you are trying to host on a shared host! but if you're asking questions like this, i want to again point you back to my top point.