It's because people don't have their mirrors adjusted appropriately. They should be adjusted so that your head is almost touching the glass to just barely see the driver side of the vehicle. Then lean the same amount to the right for the passenger side. When done this way, there is no blind...
Posted it here: https://www.bronco6g.com/forum/threads/what-did-you-do-to-with-your-bronco-today-%F0%9F%91%A8%F0%9F%8F%BB%E2%80%8D%F0%9F%94%A7%F0%9F%A7%B0%F0%9F%9A%BF%F0%9F%9B%A0.18089/post-2000539
That's what I have.
Save yourself $10 and order the two door set. I think they're also longer than the fronts on the four door set you posted.
https://www.ford.com/product/door-sill-protector-kit-by-tufskinz-badlands-logo-badlands-edition-3door-p2828395590
My two cents.
There are no blind spots with the factory mirrors when adjusted properly.
To properly adjust: You should put your head against the window and adjust the driver side mirror all the way out until you just barely see the side of the vehicle. Then lean far right and do the same for...
Based on the picture, it isn't. You can see the bottom edge of the plate on the Bronco. It matches the bottom of the Maryland plate on the car next to it.