I think this is assuming two things that are not in evidence:
1) Most people want to work from home, enough that they would feel significant envy of those who do even if their own job is one that cannot logistically do that (eg, plumber).
2) The people working from home are doing so in such opulent luxury that it creates more envy on top of that. ("...sitting on the beach")
It's quite plain from this forum alone—a forum which is heavily skewed toward knowledge workers of various types, and especially computer programmers, a job which, in terms of its basic requirements, can unquestionably be done from home—that if #1 is true, it is not by a vast margin. Many people clearly like going into the office. Many people with jobs involving in-person manual labor clearly love their jobs.
I think that the kind of "fairness" you mention in your second line is, indeed, very important—but I think that it's more about "you could be letting me do XYZ, like they are, but you're preventing me for arbitrary or selfish reasons," not "they're doing XYZ, but due to something fundamental about my circumstances, that's impossible for me." That is to say, it's more important for everyone whose job can be reasonably made remote to have the option to do so, than for every job in the world to have that option, including the ones where it's physically impossible. People are generally pretty good at understanding the inherent tradeoffs in such things, especially when they come to them after the initial transition has taken place and make an informed choice (obviously there's going to be more friction in the transition time—I don't think that's avoidable).
In short, I don't think there's more to worry about here than the already-existing (and likely permanent, at least until we get true UBI or something) state of things, that some people who have fewer options in the career they can choose to go into feel resentful of those who have more such options.