The window seat is not really functional because of the table. Can you push the table up to the bench and actually use it for its intended purpose? If not, I wouldn’t add anything that would draw attention to it. Or take it out and repair floor and wall.

Yes, you can push the table over and use it, but it is a nice place to perch with a drink, even while guests are at the table. I don't intend for the pillows to be used as formal seating, just more for decoration. thank you

I would remove all of those little pillows. I don't like that look at all. To me it looks messy and cheapens it If you're going to keep that bench seat separate from the table, then I probably wouldn't put any pillows on it. I think the pillows are too much right next to all of those chairs. I would just keep the view clean out of the windows. If you feel you have to, then you could do three long bolster pillows (one for each window) and just do them in a fabric that coordinates but doesn't match to the existing cushions. If you feel you have to keep the existing pillows, then at least group them together at each wall point between the windows to give them more impact rather than just scattered along one by one.

Hold the phone. It’s already narrow. Can one even sit on it comfortably if bolsters are added? The pillows at least can shift around if someone needs the full depth for comfort.

Interesting responses so far.
I think your window seat works nicely as a perch for viewing your beautiful view. Because of the angle of the window seat, it could only work for dining with an oval table. The idea of bolster pillows instead of throw pillows is good, but you should do them in lumbar pillow size because bolster size is too large for the bench. For pillow fabric, I would try to match the silver color so it won't attract too much attention.
I agree with the comment that the seat cushion looks a bit thin as it is, but most people carry a bit of cushion on their backsides and if the cushion works for you, it's fine.

for aesthetic purposes, the window seat is too thin. Also the square pillows could be larger.

That seat is pretty shallow already so adding a cushion to the back will really make sitting there impossible but I do agree the seat cushion should be at least 2 x thicker but that will throw off the proportions too . IMO a poorly designed add on that doesn’t really work at all.