Another option although it's not specifically a glass cleaner is M04 Heavy Cut Cleaner. I lived in Oregon most of my life and it rains enough there that most cars that are parked outside for any length of time end up with water spots on the paint and the glass. When you detail a customer's car you can't make the paint shiny and then leave the water spots on the glass, it doesn't look right and customers expect everything to be clean and shiny.

As such I usually used an aggressive paint cleaner by hand or with a rotary buffer to polish out all the glass first and then do the paint polishing work.

The product I usually used was M04 Heavy Cut Cleaner, it uses a large chunky diminishing abrasive and it was the large size of the abrasive that enabled it to cut off the film built-up on the glass but at the same time the abrasive wouldn't scratch the glass so it was a safe option to use.

There are other products that can do this to, M04 was just something I had with me most of the time. Shared this on the MOL forum years ago and a few months ago one of the members used this product to remove the water spots of their car's glass and actually wrote a pretty good article on the process.