You missed a lot. There are so many things wrong with a statement like this.

1. A global comparison necessarily includes roads all over the country, the bulk of which being intercity motorways. Given that motorways and local roads are maintained quite differently, for a discussion about the viability of our roads for use with scooters then, which don't use these roads, such a bias renders this metric useless.
2. It won't include surfaces which are likely to be used by scooters, such as pavements and cycle lanes, let alone the availability of either.
3. It's also likely not to include negative cultural norms like:
   • Parking in cycle lanes
   • Parking on pavements
   • Double parking
   • The average size of vehicles and the visibility the drivers have

The biggest problem though is that it's just a bad argument. Having roads better than another place does not make our roads "good". At best it establishes ourselves on a spectrum of mediocrity. I saw this constantly living in Canada where people would talk about our mass transit as "better than what they have in the US" like that's something to be proud of.

Our roads are objectively shit. Potholes are everywhere and the pavements are literally crumbling. For a scooter, these are all serious hazards because of the wheel diameter. Those are objective facts, so lets stop with this "well at least we're better off than ${someplace slightly shittier}" because it ignores the objective shitty state right in front of us.