They could fork Firefox or Chromium, poach some current developers, hire some more, and assert a strong presence on standards.
Do I think a government can fund a group of developers to fork some existing code and run with it? Yes, I do. Radical concept, I know...
Why do you keep bringing up Chromium anyway? We're talking about Firefox here.
As opposed to CERN being easy to build!? I'd say is totally doable, but it doesn't promise filling anyone's pockets at the moment so traction is hard. Who knows, maybe in the future..
As with many things, it's just like Dark Helmet said in Spaceballs: "Evil will always triumph, because good is dumb."
Not to say that the US (or Mozilla or Google) is evil and the EU and LATAM are good (LATAM in particular is a really screwed up place, with a few exceptions that aren't as broken like Chile), but while the US obviously has its problems and does really stupid stuff (see the current election), other places do incredibly stupid stuff too (see Germany disarming, shutting down all its nuclear power and trying to make itself dependent on Russian fossil fuel energy). Honestly, I think the main reason the US is still doing as well as it is (see the strength of the USD) is because everyone else is so busy shooting themselves in the foot with a shotgun.
So yes, I totally agree: theoretically it should be pretty simple to just fork Firefox (or Chromium, though I think the former is a much better choice so we don't the whole web dependent on a single browser engine, if for no other reason), poach some current devs, hire some new ones locally, and then become the new "open standard". But good luck getting some national government (or even a group of them, like with the EU) having some vision and backing such a move.
Honestly not a bad plan.
They aren't necessarily working for Mozilla now, because they can see right through a lot of obviously bad moves Mozilla has made, and ridiculously overpaid executives.
"Go where the biggest paycheck is" is people who care more about career than mission. Why would you even want those people, unless you can't get the mission ones.