!rant

Stupid customer insists that the website must have the *same fucking UI* even when seen on mobile.
Where the fuck are your eyes, don't you see that a big complex table just doesn't fit the fucking screen of your crappy phone??? Of course it needs to be layed out differently.

I don't know if I should politely reply "no", or just don't give a fuck, deploy it, and then let him realize how much he is stupid.

what is his reasoning for that?

Maybe the client means he wants a reponsive UI and not different versions for different devices.

Yeah, this is a frustrating thing.

Is it trivial to show him a test site, or screenshot? I literally have a staging site that a particularly indecisive client of mine has 24 7 access to. He can review the changes he asked for and go back on them if he sees something, without hurting live site.

But chances are, he wants to see or do something specific he's not thinking of telling you. Maybe it's view the top of row of the table every 5 minutes and he doesn't like expanding the hidden content on mobile.

But don't be afraid to charge. Something like "what I've provided is standard and in line with best practice. I'm afraid it will take some back and forth, trying new ideas, until we get a design that you really want. Unfortunately i would have to charge for any revision after this, but please see option 2 for mobile site which shows what you describe. And we'll go from here" Idk the situation but this is what i might try...

Just disable responsiveness and charge him for that.

Don't be afraid to say no. Most clients think that their idea is the best, but with a little bit of explanation you can show and even prove them that there is a better solution.