what you build the front end is a matter of taste/familiarity, go is just good for building sophisticated web services in a neat little package with front end launcher baked in (using embed)

yes, i'm pretty sure that fiatjaf's background is in doing golang web dev, he knows also the web dev to a fair degree but is kinda more back end oriented

what is not much fun to do with go is desktop/mobile apps... you may recall keybase - that is a similar architecture, go does all the compute and logic at the back, and on the front is an electron app... on mobile, you can embed go services in the back end but it's more tricky to plug it into flutter or native java or whatever

native go GUI programming has been very neglected, the best framework now is fyne, but it's still hardly what i'd call production ready