Are cloud and streaming handhelds worth it?

For the right person on the right network, yes — as a specific tool. A cloud handheld lets cheap hardware show current-gen visuals your local chip could never render, which is genuinely useful on strong, low-latency Wi-Fi and frustrating on anything less. The permanent trade-offs are a subscription, dependence on a connection, an input-latency tax, and games that stop working if a service closes. Most people are better served by a native device that can also stream when it makes sense; a stream-only handheld suits a specific home network and play style.