People who live in Western cities have no fucking clue what fruits and vegetables are supposed to taste like.
It’s like a running gag that my father complains about supermarket tomatoes, but after travelling through rural places in Eastern and Southern Europe and a little bit in Central America, I totally get it.
Grow your own and the difference is extreme between that and a mealy, flavorless storebought
Remember when toothbrush advertising demonstrated how the brush was so soft it wouldn't affect a tomato, let alone your gums? That demonstration makes no sense now.
Stuff is often in season in the US, and at that time, it's generally good in the supermarket. Then there's when it's not in season.
Contrast green beans shipped from 1500km away on a boat, arriving 2 weeks to a month later at the store, kept "fresh" by all sorts of waxy residue, and other "agents" sprayed on them with .... green beans canned within 2 hours of being picked.
Where I grew up, in a rural area, we had a local canning plant. They'd get farmers to plan to harvest on a schedule, and they'd literally be canning as the farmer drive trucks up with produce. No joke, they were canned within 2 hours, often faster, and that's how it's done these days.
Which has more vitamins? Which has more nutrition? I'd lay a bet that the canned stuff is far better, far better than something that has artificial stuff sprayed on it so it looks good (artifical 'wax', and various chemicals to keep it "fresh"), and spent weeks getting to the supermarket.
Oddly, I've seen people dump out the water in the can. What? That's where a lot of vitamins live!
Food just tastes better in other countries.
This should be corrected to fruit and vegetables taste better in regions where they are grown. Which is obvious, because picking them before they are ripe and transporting them thousands of kilometers for days or weeks is going to yield a less tasty fruit or vegetable. Also, plants bred for longevity of their fruit will obviously not be optimizing for taste.
Personally, when it comes to fresh produce, I'd rather only be able to eat mostly what can be grown in season somewhat close to me (which would include greenhouses), rather than be able to get anything all year round and having it suck.
You really have to define what you mean by "supposed to taste like." As in "supposed to taste like what occurs in nature without human intervention" is very different than "supposed to taste like after humans have spent generations cultivating them to be the sweetest variety" which is different than "supposed to taste like when they are cultivated to optimize for logistics."
I suspect what you're referring to with the tomatoes is the last example, because they have been grown and picked to best withstand transit.
Where the problem lies is the changes made to fruits and vegetables to make them last the long journeys that they have to make from places that have longer growing seasons or cheaper labor.
Try a locally grown heirloom tomato in the summer in the American Midwest and you’ll get a phenomenal tasting fruit. More interestingly, try a bunch. It will be hard to say what a tomato is supposed to taste like because of the variety in flavors that come from location and breed.
Americans shop with our eyes, not our mouths.