You could use it to ensure greater consistency. If they built a simulation system similar to FM to monitor games in real time, by feeding the system information on correct decisions, the bot referee should be able after some time to calculate the most consistent decision. You'd need chips in alle the balls, all the boots and maybe even censors in the shirts. Their weight, height and body strength could be measured beforehand. Let's say a player is bumping into Salah and Salah removes his footing to go down, system should be able to detect that in real time and give a decision on that to a ref in less than a second. Beep - no foul on his watch. Another situation is when a defender goes down to protect the ball out wide when being pressured in a defensive position, usually a free kick no matter how hard the contact, here the system could make a non biased decision based on impact. Does that constitute a penalty if it happened in the box? You could really plot in a blueprint for how the rules should work and use that as a reference point for consistency. How are you going to argue something was soft, if even if it's soft, it's always soft.
For me it would be the most important change in refereeing with the use of technology because it actually improves a system. It wont completely remove human error, but it will take a lot of the guesswork out of the simple decisions and make the game run more smoothly. It would be a lot less fuss if everyone would just agree on the rules and focus on playing football.
These days we have rule changes every year, different practices are introduced and thrown out as soon as they come. Nobody can agree on what the rules should be, and a different explanation is used for the same situation each week depending on who gets the decision in their favour. The integrity is at an all time low for me and it's killing the sport. The competitive element is threatened by oil money and political investment as it is. I also think such a system could be rendered out for the public to explore, not hidden. Every decision would then have an explanation behind it and updating it by public opinion would be easier than having a meeting with 23 refs who should all just change at once.