Well, "normal" Go binaries grow somewhat quickly as you add libraries. I don't think WASM is growing faster, it just stings more when you're looking at transferring them in realtime over a network. A 20MB binary is not really anything to a modern system, not even a Raspberry Pi. But a 4MB WASM executable can still hurt.

(Though, sadly, only if you care. I just double-checked CNN's website, and given that it autostreams video it's hard to give a concrete "it took this much to load the site", but if I look at how much data was transferred before the home page stopped jumping around and rerendering and unblocking grey boxes and spinners, it was around 20MB.)