The most important thing in a market economy (aka economies that are not communist), is competition. Competition is the primary thing that keeps costs low. Without it, we (consumers) are all toast - however it'd be great for the stocks of those few remaining airlines (with enormous upside potential). Flying in airplanes is a mostly ineclastic good. this means, people can't just stop flying. All this is extremely bullish for the remaining airlines, in the long run (2 years+).
The last couple weeks have shown this to be quite untrue.
If this pandemic leads people to realise that so much flying really isn't necessary, and actually changes long-term behavior, that could be at least one silver lining.
If people decided to enter markets purely based on profits then shouldn't there be a bunch of competitors for Google's search engine biz?
As to your second part, search engines aren't a high profit business; advertising is.
Since all of the infrastructure already exists it shouldn't take that long to scale back up.
Sorry to be crude, but it beggars belief that people can afford flights, realise why they're discounted, and yet be so short sighted.
Seating like we used to have a few decades back is available. It costs about the same as it used to. People seem to forget how expensive air travel were back in the days, no wonder it was more luxurious.
That's part of the reason the airline requires you to sit in allocated seats - so they can notify the people sitting in neighbouring seats if you have a notifiable disease.
My personal hypothesis is the low pressure ultra-low humidity air in planes dries out mucus membranes in the nose and throat making it more likely for airborne things to get in.