Very harsh on Hamilton. Very, very harsh. Since the second flying laps of Q2 they looked clear favourites and dominated the race. Mercedes had ample opportunity to pit themselves (twice, once under the VSC) and chose not to do so, but either way it's very hard on them, especially with race control changing their minds on letting lapped cars overtake.
I could see both sides on the lap one incident. Verstappen did leave Hamilton nowhere to go (which both have done this season with no penalty) and equally Hamilton didn't back off anywhere near enough. Two wrongs don't make a right stewards.
Shame Perez's epic job in holding up Hamilton, which might be the second best racing all season after Alonso in Hungary, will likely be all but forgotten in the coming months.
A Mercedes customer causing the safety car which cost them the driver's championship. I guess that's Renault confirmed as their engine supplier for 2023.
Should Mercedes have pitted? In hindsight yes, even if Verstappen had stayed out, they still would have had a high chance, but instead they chose to try to keep track position on tyres which had no realistic chance of doing so.
They've had the fastest car since Silverstone, had question marks over their strategy before and again will have today. They were put in a hard position but chose the wrong choice.
We can wait and see if the FIA make any statement about their reversal of decision to let lapped cars overtake, but it's very, very harsh on Hamilton.
It doesn't make Verstappen an underserving world champion. He's been controversial (as has Hamilton at times) and certainly hard racing, but he's also been great for much of this season. 2021's championship will likely be looked back on as having a lucky champion, but that's not deserved. He was lucky in the circumstances in how it was won in the end though, just as Hamilton was in 2008.
What about Max weaving down the straight?
You'll get warned about it before getting any penalty, as long as it's not outright dangerous, which it wasn't. Never in F1's history has a driver been given a penalty for weaving (before a braking zone) without first having a warning.