Your kitchen is beautiful! Before buying new counters or countertop backsplash I would try and find another tile person for a quote/thoughts. I’m no expert but maybe a talented tile person could adjust or tweak the work so the unevenness wouldn’t be seen.
If this doesn’t work, the only alternative I think is doing the counter as a backsplash. Unclear if you want it everywhere or just over stove?
You could also look into fake stone for the backsplash, but a very neutral or blank so it doesn’t conflict with your counters.
On who to blame, not sure. Who should remedy it? Might take a team. Is it the window sills to cabinets not level, maybe a cabinet problem. Is it the room isn’t level, could be contractor or foundation problem…. Beautiful beautiful space!

Another option: zellige tiles are super in right now and have beautiful glazes and neutrals. These might be a good option bc they are handmade tiles with rustic elements and not so clean cut as subway tiles. They also need little to no grout.
You could also do zellige tiles vertically or subway tiles stacked vs the traditional horizontal format if the lines won’t line up?

how much is "off" and where in particular/ tile placement with the correct tile and cuts can "ease" discrepancies. Dont rip things out for heavens sake. Find tile people ..have them in to look this over and get quotes. [do you have to use this guy?] a four incher all around, and then insertion of a chevron or herringbone or something fairly busy above stove might be a solution but its not clear.

@herbflavor @Julie Schmooley

Thank you so much for the quick responses. Answers below...

Our "contractor's guy" doesn't speak good English, but we got that there's a 1 inch difference (yup) between the height of the windows. It was unclear where and how bad the levels are off elsewhere. There are 5 more windows that continue on the left and around (see new picture), so it is really important that the line continues consistently all the way around and across.

Another quote from several weeks ago when I anticipated this problem said that the right, single lower cabinet needs to be shimmied up by 1/4 inch. Not insignificant.

I asked for another guy to come out and assess. Not scheduled yet. He seems to be the most knowledgeable, so I am hoping he can fully diagnosis and provide more concrete solutions.

These are the tiles we were going with, my concern is that the variation in color may highlight more of the discrepancy.

https://www.bedrosians.com/en/product/detail/cloe-ceramic/?itemNo=DECCLOWHI28G&moq=true&gclid=CjwKCAiAs92MBhAXEiwAXTi255pEjDEpJpr-qA7rqhQ7pCPgnWHVAVwo6BwJp2woIRVbPGUqB7LqqxoC7ukQAvD_BwE

I guess I don’t understand where you are unlevel. If the cabinets are off does that mean your counters are slanting? Do things roll off of them? I am no pro but I think 1/4” shim would be acceptable. But 1” unleveled is a lot - but I don’t understand where this 1” is happening. Windows are crooked? Countertops?

Your contractor messed it up. Theres probably a lot of invisible stuff too. This is a FUNCTIONAL issue, not just a decorative one. Didn't he even own a $100 laser level? He owes you a redo. Which should have happened before the counters went on.

If you don’t want to force the issue, and agree to live with the major problems it will cause, then the only solution for the backsplash would be back painted glass, in smaller sections than usual. A uniform calm appearance. Or small mosaic glass tile, set diagonally. That’s the only things that will fool the eye enough.

You do not want the extra weight of a stone slab carried by unlevel cabinets. You already have enough of a risk with that for counters already. You may get cracks and splits. No extra weight on top of that. Including any standing. Ever. Get a better articulating ladder to change your lightbulbs and dust,

with all the individual window openings...was this an addition.....new construction.....new framing? I guess I'd feel a little more like working w the aesthetic w the tile as the thing to adjust rather than anything else such as counters/cabinets. Reason is that looking at the pictures does not show anything amiss. Reason is that swapping the chosen tile where straight horizontal alignment is key for another tile might mitigate this. Get the help from the 2nd guy. I'd be willing to swap tile...reduce tile on the walls generally

A good tile person is well used to saving the day! So I would find the tile person first and then select the tile with guidance.

First of all the kitchen looks really nice!!

Where’s the height difference?
Measure it yourself at least to know for sure.
Hopefully it was the language barrier and it’s less than what you thought ...

I’d finish up the project, have the contractor wrap this up... and have someone new come in for backsplash...

I love that tile I wanted it but hubby vetoed haha I think the variation in color could work to your benefit and if you did a white grout it would be even less noticeable!