Wild Walker

Definitely 6600 XT then

Can you even find a 6600 XT available for a price you are willing to pay? They seem so scarce compared to 3060 right now.

depends on whats cheaper and in stock but if you want rtx or the nvenc encoder for streaming or recording games id go 3060 but if you dont care about those and the amd is cheaper which is very likely go for the 6600xt

I agree

DLSS seems to be the future of games, but FidelityFX shows promise with similar boosts. Personally I would go with the 3060 based on my experience with NVIDIA and more support for games and settings like RTX and DLSS, but that's just me.

6600 XT has much better performance (20-50% increase depending on game and settings), at the cost of DLSS. They have FSR, but there are much more games supporting DLSS than FSR. Seeing your game list, the only game that doesn't support FSR but does support DLSS is Warzone. RDR2 too, but it's easy to add it to that game.
People always say Nvenc is better and stuff, but with 6000 series the AMD encoder improved a lot, and honestly the difference isn't big enough to notice. Please, do you research before recommending a card because the previous gen didn't do well in that area. Just don't get the 3060 for Nvenc. Here's a video showing how small the difference is. You only notice it when zoomed in.
6600 XT is also getting better at ray tracing, but the 3060 is still a winner in this area. 
AMD's drivers seem to be improving, while Nvidia is also improving but not as fast. Their drivers are also much better for Linux use, if you care about that.
 
I would definitely get the 6600 XT, unless you care about RT.

I'd personally go with the LG but I'm biased, having an LG monitor. Just saying this because I've never had a problem with it, having said that, you could get a bad unit from any manufacturer. One potential down side is it only supports 8bit colour via dithering, having said that, perhaps this is true for the others, I don't have time to check all of them out. If you're only gaming on it, it might not make a difference to you.
 
It's not something I replace often and when I do, that's the point when I put in all the research so whatever I learn is out of date really fast. Anyway, I'd just say look into the reviews of the three you're looking at and see which comes out on top on average. 
 
I wouldn't get the same one again. Perhaps it would be fine, on the flip side, you could end up wasting your time.

It's normal to get some glow but this seems to be particularly bad, especially the brighter patch middle right. I'd request a replacment, there isn't much you can do and if that also has the same issue, you want to look at a different model.

Here's a shape comparison with your current mouse, if it's any help:
https://www.rtings.com/mouse/tools/3d-model-shape-compare/steelseries-sensei-ten-vs.-logitech-g703-lightspeed-wireless-gaming-mouse?orientation=3D&overlap=beside
https://www.rtings.com/mouse/tools/3d-model-shape-compare/steelseries-sensei-ten-vs.-razer-basilisk-x-hyperspeed?orientation=3D&overlap=beside

I would recommend the Logitech G703.

I found a site where they review alot of mice and they have a special search option to find the best mouse that will fit for your hand and grip type, and from all the mice i had in my list the G703 and the Basalisk are recommended.
So now it is just going to be which one will i go for.
https://www.rocketjumpninja.com/mouse-search
 

Maybe the Steelseries Aerox 3 or Steelseries Rival 3 Wireless or the Glorious Model O Wireless then? Of the ones you mentioned the G703 and the Basilisk are the 2 best IMO, but they are very different from the Sensei, so they will definitely take some getting used to.

Out of those the cooler master's but if your in the US my favorite for a $100 is the PC 37x on massdrop