.gg and .io are being used for novelty value.
And for .io of course that one is/was popular among tech companies because it looks similar to “I/O” (input/output).
It is a little surprising given their field that they didn’t also grab the .io.
I found: kubernetes.io , sentry.io , codepen.io , itch.io , not to mention lever.co , elastic.co and last but not the least, notion.so .
A tourist attraction in Guernsey can very reasonably use .gg and maintain full credibility.
Thinking through websites I use in Denmark, I struggle to recall one that isn't .dk.
Supermarkets (netto.dk, foetex.dk), public transport (dsb.dk, m.dk, cph.dk), newspapers/TV (politiken.dk, berlingske.dk, dr.dk), University (ku.dk, au.dk), local government (kk.dk), other retailers (computersalg.dk, proshop.dk, elgiganten.dk) ...
The largest grocery delivery company uses nemlig.com, and Ikea uses ikea.com.
As another example, if I'm applying online for a visa to Thailand, that site had better end .th.