Certainly there are companies that pay remote lower salaries but this isn't always true. Some companies want the best talent and know one of the best ways to make that happen is to not try to under pay any employee that you can find a reason to under pay.
I also disagree that you're competing, at least directly, with someone from the countries you listed. Depends on where you are and who you are, but as a remote employee I'm still working from the same timezone I was working from when I was in the office, it's very cheap to fly me onsite as I'm next to a major airport, and am a native English speaker. Hiring someone who wants to work from their home in the US isn't immediately the equivalent of hiring someone from another country with possible timezone, visa and language barriers.
I'm not really a fan of the term because it covers a huge variety of people and the most vocal ones are working here and there and largely just prioritizing the idealized "digital nomad life".
Then there are people, like you said, who are renting apartments for weeks/months, prioritizing quiet work spaces, and often continuing to hold full time jobs.
I'm kind of in this category right now and am certainly never working from the beach. I went to Latin America so I could find apartments with good internet and continue to work in the same timezone that I started out in.
Answering as a current employee. When these were being phased out to start to lower costs students and graduates reacted strongly that they felt they were a large part of our value. Part of what makes us "us". As another commenter in here pointed out: bootcamps aren't for everyone.
We were up front about these things being part of our program because we want to focus on the human aspects of people as much as technical skills. That meant some people were better suited to join other places, but some people came specifically because of this part of it.
I also disagree that you're competing, at least directly, with someone from the countries you listed. Depends on where you are and who you are, but as a remote employee I'm still working from the same timezone I was working from when I was in the office, it's very cheap to fly me onsite as I'm next to a major airport, and am a native English speaker. Hiring someone who wants to work from their home in the US isn't immediately the equivalent of hiring someone from another country with possible timezone, visa and language barriers.