I am not missing the point. The person is giving an actual answer from his own lived experience and you are saying they are rude for it. I encourage you to expand your network of foreign friends so you can ask them about the food here vs at home. They will almost certainly say the exact same thing. The tase and the smell of the food here even if they make it will not have the same taste and smell back home.

I have a huge network of foreign friends and have lived abroad for the last decade.

Again; you are missing the point. It has nothing to do with whether the food is “authentic” or not, which is itself a highly debatable question. It has everything to do with the way you communicate to people when disagreeing with them or criticizing their ideas.

If you don’t care that people will immediately think you’re a pedantic, difficult person, as long as you get to be “right”, then sure, feel free to disregard what I wrote.

Have you asked them about the food here vs. back home? Will you return here when they tell you the food tastes different just like what the person said?

The guy said two sentences. You may think it's rude but it's probably the language barrier and he's just trying to give his honest perspective and there was no rudeness intended.

"The food tastes a little different" != "The food is entirely inauthentic"

Authenticity, in other words, is not an absolute. It's a spectrum, and you can get pretty darn close to the "authentic" end of said spectrum without needing to literally import foreign water.

It's a spectrum and OP offers to get closer to one end of the spectrum when it comes to authenticity. What's the fuss about?

I have lots of foreign coworkers and enjoy going to restaurants we find. No one sits there and complains about how this doesn’t taste exactly right so what’s the point in trying something new.