That offers limited utility since there are very many plays that end with the ballcarier nowhere near the hash marks or sidelines.
They’ve tried to do that for years. The umps are still more accurate.
How do they know the umpires are more accurate? What are they comparing umpires calls with to check for accuracy?
I’ve long-said there should should be sensors all over the place in football. Two in the ball, kneepads of running backs, shoes of receivers, etc. The less human decision-making there is in the game (from a refereeing point of view, that is), the better.
The big stumbling block to this would be durability. There would likely be longer “pad replacement” breaks than their are currently “under the hood” breaks.
On a separate note, the correct response to this thread title is “What technology? I just check my shorts”.