Agreed. Several of the contracts I was responsible for in my old company were worth $1m+. On the rare occasions things were not running smoothly, there was always a way to settle amicably without recourse to legal action, with its ongoing costs and wasted time.
And the value of Upwork contracts would make it unlikely, as you rightly say. Plus there is the opportunity to have additional T&Cs.
But still an interesting question raised by a broker. Thanks.