Lots of folks use Golang on the client side, even on mobile (for which Go has really great support with go-mobile). Of course it adds around 10-20 MB to your binary and memory footprint but in todays world that's almost nothing. I think Tailscale e.g. uses Golang as a cross-platform Wireguard layer in their mobile and desktop apps, seems to work really well. You wouldn't build a native UI using Golang of course but for low-level stuff it's fantastic. Tinygo even allows you to write Golang for microcontrollers or the web via Webassembly, lots of things aren't supported there but a large part of the standard library is.