What do you mean I'm not "totally wrong"?

I'm 100% correct and the strategy the armwrestler chose was irrelevant to the outcome of the match. It's not just a probably could have won by pulling from the start (it is not a push movement despite what it looks like — armwrestling rounds are literally referred to as a 'pull' because we are pulling back more than we are pushing to the side), it's definitely.

Literally the only reason the armwrestler chose not to flash pin was, as you mention, for entertainment.

It's actually a suboptimal strategy to not start by training to gain some advantage (cracking their wrist back, pronating over, opening their bicep, dragging elbow back, etc.) because there are maybe ~50 things of varying importance that your opponent might be focusing on and trying to accomplish, and if ALL you do is try to hold isometrically, they will get at least 1 of them and you will gain nothing in return, just a worse position.

I don't know of a single pro armwrestler who attempts to start their matches with an isometric hold, for that reason. They certainly do not attempt to hold in a supinated-but-not-bone-locked position (like that in the video), and almost nobody except Crazy George shoots for a supinated-and-bone-locked position (NOT in the video) from the get go. It's simply suboptimal.

Tiring your opponent is a strategy, yes, but it more often looks like achieving a winning position and then 'bleeding' them, or actively regripping up and up on their hand in a neutral position or otherwise ekeing out small advantages. Nobody simply tries to tire their opponent by remaining in the same position and 'holding'.

If you would like to learn more about the sport r/armwrestling is a good place to start! Alternatively, Voice of Armwrestling is a good instructional Youtube channel.