Windshield Edge Protection Tape - Necessary?

It's not just about stress cracks. You would also have to design the glass to fit directly against metal and not leak water.

I think you'll find that a 4 meter piece of tape is much less expensive than redesigning both the glass and the opening to work properly without it.

It's there to seal the window to the opening, make it fast so it does not move around and I believe it's butyl rubber.

You're right! It works great.

Cracks generally start from the edge because of the old adage..."between a rock and a hard place". The flexibility of the material is greatly reduced on impacts due to the anvil on one side. Stress fractures due to freezing conditions occur due to lack of movement, again, because the glass is affixed to to an object, which changes shape at a slower rate, and is attempting to relieve stress.