Liverpool got what they deserved in my view. I reckon if you showed that replay of the Fabinho foul to competent referees like Taylor and Oliver, they would say Red Card every day. I once saw Rooney sent off at OT for a similar tackle from behind and the referee was 100% right to send him off.
The only question I would raise is did Coote have a good angle to see just how bad a challenge it was? (and I'm not making excuses for him). When VAR was reviewing it, what comment did Coote offer as to what he'd seen? If there was any doubt in Coote's mind and VAR did not advise an OFR for a clear and obvious error, then I'm afraid it raises questions for Webb as well as the VAR. Is he making VARs so reluctant to intervene that wretched fouls like that are not being adequately punished? It's not just a question of did a referee see an incident; it's did he see it clearly enough to make the right decision?
The Robertson challenge wasn't clever either but YC was probably ok. Incidentally, it looked to me as if Fabinho expected to be sent off.