Travel is a set of unique experiences that form unique memories. Part of what’s addicting and pleasurable is that it helps slow down the perception of the passage of time, among many other positives.
It’s also self reinforcing in that when you think back, you tend to disproportionately remember travel vs other experiences.
There’s clearly a lot more benefits than that, but it certainly seems like a significant factor.
When I travel, either I want people or I want solitude. Most of my enjoyment from traveling comes from seeing family and friends, and it really doesn't matter that much where we're situated. But if I have neither, then being in a sea of people is really worse than just being at home. In that case, I want to be alone, and I can easily get that by driving 1.5 hours into the mountains where I live.
Travel isn't a bad thing, in fact it can be a great thing. My problem is that we've made travel out to be a grandiose life achievement. In the near past and for millennia, humans spent most if not their entire lives in one place, and there's nothing wrong with that.
However, if you get away from the "tourist" spots, every place is unique and does offer something interesting to experience.
My wife and I were driving back to our rental in France from someplace and stopped for lunch at the only restaurant we could find in the little town in the middle of I have no idea where we were. Very little English spoken (we don't speak French, but can manage with a few words and technology) and had a very enjoyable meal and a little sightseeing in this small town.
Not saying that everyone enjoys that kind of thing, but if someone travels to Paris, for example, and has their sights only set on the popular things, Eiffel Tower, Louvre, etc. They're missing so much more to the city. Yes, certainly plan on seeing what's popular because that's why you went there, but also spend at least half the time exploring the little gems that every city offers that unique to it.
And for the love of everything, don't eat at places you can eat at home every meal just because you know it.
As an example, one thing I do enjoy is finding and visiting quirky little museums. The sort that might only be a couple of rooms worth of items. By nature each one is a new experience for me. But if I take a more abstract view I could say "I'm just looking at another quirky little museum".