The 380 will not be a significant player in freight for a very long time. It can't operate the same services a 747 freight unit can, door loading efficiencies. The drivers cabin is up top in a 747 so you have clear run into the main loading bay. the 380 can't do that because the bus driver sits in a half-level in front of both upper and lower floors so there's only side-door loading.
Yes. We all saw 380's loaded to the gunnels with PPE during covid. No, that doesn't mean they are all going to wind up doing freight. What I read suggests it will carry less, or only very close to a 747 in most cases.
It's working fine in long haul passenger roles and will continue to work well for state funded airlines like Singapore and Emirates as well as ANZ and Qantas and China Southern (they've pulled out now). BA and other European carriers are a bit half-pregnant on it. Singapore and Emirates alone probably have 1/2 of the entire fleet worldwide. QANTAS has 10, maybe options on 2 more. Its fleet looks to be moving all airbus with the recent purchases, Jetstar run the 787.
At one point Emirates flew their mostly empty 380s from Brisbane to Auckland to park: it was cheaper considering all the economics, and the opportunistic passenger load you can pick up there, than parking in Brisbane. I am sure it wasn't literally "parking fees" but I flew that segment a few times and it was less than 20% load both ways.
The lack of US market isn't impacting it's viability in other segments. Shutting down the line was a mistake in my opinion, but I'm not an economist. That said, the other lines (350, &c) are running fine.
The a350 is a better craft than the b777 for passengers. Engine noise and seat economics. I've done 7+ international (AU to USA and Europe) flights a year for the last 20 years and so as a passenger I think I can compare aircraft experience. I am told in engine burn its better too but the differences here would go to TCO and I can't comment, I don't run an airline. If you have to do the operations research on buy new, lease new, buy old, lease old, outsource, insource, end-of-life retained value, flight profiles, load, its all complicated.
It's too easy to claim "this aircraft is better" when you're an armchair planner.
All major aircraft are state subsidised in development no matter how hard Boeing or Airbus try to mask it.