Is it possible they're selling links to monetize?
Most of these sites have terrible DA and many things suggest to me that 99% of those people, if asked about their DA, would struggle to name the public official in their district who brings cases on behalf of the state.
They are mostly trading links for goods, albeit without any direct contract/negotiation. It's just understood that if they get a few freebies, they will write a review and that review will serve as a link. And they are smart enough to know this. So they publish an unending series of positive, glowing reviews with links to the businesses reviewed (using that term loosely).
I think the best way to think of 99% of travel bloggers is that they are your free, volunteer PR team, but sadly, are not very good at it and any discerning reader sees right through the BS. Which is part of why they have so few readers. They are literally afraid to publish any bad reviews.
I do need to say, that my comments do NOT concern traditional media. We have had genuine travel journalists from top-shelf newspapers who are under strict rules to not accept anything for free. In some cases, they only tell you they were there once the review is written. A review in the NYT or LA Times is a real thing.
I think there are two things going on with the influencer/tourist destination circle jerk:
1. The "buyers" mostly judge blogs by looking at it and saying "wow, that looks nice" and then ask the blogger how many monthly visits, take the blogger's word for it and stop there. So ignorance on the part of the buyer. When I ask them whether they look at tools like Similarweb, SpyFu, SEMRush, AHREFs, Majestic etc, most of them have never heard of any of these tools. Most don't even do a site: search to see how many pages are sharing those pageviews every month.
2. Everyone wants to be a travel blogger. Some days it seems that there are as many travel blogs as there are travelers. And 90% of them are just doing it to pick up freebies or even just minor discounts. It's hard to see how their articles would be of interest to anyone. The very, very best of them read like in-flight magazine articles with titles like "Five Perfect Days in X." No Tim Cahill's here. So though there are some homerun travel blogs or Instagrammers who can move the needle, they are few and far between. For the most part, the amount of traffic you need to stand out as on of the better low-end bloggers is paltry. Sites with 10 writers and 10,000 posts will brag that they have 10,000 visitors a month.
Next time one of the egregious examples comes up, I'll share it on the inside so you can run your own tools and you'll see what I mean. I previously told of the woman who got angry at me because I wouldn't provide all the photos she wanted. Didn't I want her readers to have all the information they need? But the reason that I didn't supply said photos was because I had asked her to see her blog and she confessed that she did not have a domain name yet so it wasn't live. I had another self-described "blogger" pitch me on a free stay, and it turned out she hadn't launched her blog yet.
Some of these people are clueless beyond belief. In some cases (certainly the picture woman), I have reason to believe there is mild to not-so-mild mental illness at work.
So no, I don't think link selling is a significant factor here.
As I say, it strikes me that it is overwhelmingly a Golden Ring mentality. And, at the risk of offending, the travel bloggers overwhelmingly, and not surprisingly skew toward young and childless and stay-at-home moms, at least in my experience.
Some of them make it and do get the Golden Ring, of course. Most of them seem to fall into two often overlapping categories
1. Early to the platform. One person I know who basically makes a living off his Instagram "adventure" presence attributes his success to being on the platform early. He's a good photographer with a 4-year photography degree and years of professional experience, but he doesn't think he has what it would take to make if he started today.
2. They are not only good (see #1), but offer something truly a cut above others on the platform.
Combine #1 and #2 and you get people like Chris Burkard - 3.2 million IG followers for a very non-edgy Mormon who takes pictures outdoors, but damn good pictures -
https://en.wikipedia.org/wiki/Chris_BurkardBut then, Chris Burkard isn't asking for a place to stay in return for 5 posts to IG and a blog post.