Why can rugby, cricket etc have people capable of running the processes correctly and yet somehow the assumption is that we can't? Running the process to the level where you can defensibly say "we carried out each step correctly" is a minimum requirement, if they can't get that right there are bigger issues here than anyone thinks.
You're citing stats regarding judgement calls as a reason not to broadcast audio, which isn't the point. If the VAR says "I think we have a C&O error here" and is wrong in that judgement then we can debate it but at least the process is being followed. What you're implying is that they don't actually ask that question in reality - which would be a strong reason for PGMOL et al to not want to broadcast audio, but would suggest the process in reality is very different to what is laid out in theory, and is also being carried out by people incapable of following a basic flow chart.
It felt like a lot watching the game, I certainly wouldn't accept anyone trying to argue that 4 significant interventions per game is anywhere near routine.
Also, how are we defining these, was it actually 4? Brentford had I think 2 disallowed by VAR (plus/including one which was flagged offside on-field and then confirmed by VAR, not sure if this qualifies as a review?), Liverpool had 1, plus there were also quick but definitely present "confirmatory" reviews on both the Brentford 1st (for the accidental handball discussed above), the Brentford 3rd (for the possible foul on Konate) and the Liverpool goal (for a possible offside) - so depending what you're counting, I think it was either 2, 3, 6 or 7 reviews?
This is a common theme when discussing VAR involvement - people love to complain about the long difficult reviews, but ignore the positive effect of sky-ref quietly confirming what could otherwise be very contentious decisions. I don't want to be too VAR-evangelical, but 10 years ago, 3 of the 4 goals in this game would have been extremely controversial and 3 more goals would have been incorrectly allowed - all of which would have caused the temperature of the game to rise significantly.