Apparently, the French typically start with "no" because it leaves them room to say "yes" later, which is harder to go back on.
> “Answering ‘non’ gives you the option to say ‘oui’ [yes] later; [it’s] the opposite when you say ‘oui’, you can no longer say ‘non’!
https://www.bbc.co.uk/travel/article/20190804-why-the-french...