Standard or not, 120V is not what you see on receptacles. It is standard 120V in both US and Canada. But you don't normally run your household devices on 120V, believe it or not
Now it gets silly - but nevermind.
In Mexico "standard" is 127 - and it can go high and it can go low. This will trip some surge protectors some of the time. To keep our protection from tripping we have an ISB which attempts to regulate voltage to 120 (the "standard" for most appliances and equipment). Sometimes it all works and sometimes it doesn't.
Many years ago the US Navy sent me to school for over 6 months to be an electronics technician - which started with all things electrical and went on from there. It was a long time ago and I never again worked in the field. But I do remember a lot of stuff and have worked with electricity and electronics as needed in my personal life for many years. We hear lots of people say 110 or 120 or 220 or 240 and it can get confusing. But whatever. The "Standard" in the US is 120 and 240 (and in some commercial applications it is 480) and that is what you should see when you plug into an RV park pedestal. If you do not you need to be aware that something is wrong. In Mexico you should see 127 and if you do not then something is wrong and you should pay attention.
I am sorry that not everyone agrees on the word "standard" but I verified my information with the world standards shown above. This is a pointless argument similar to so many others we find on this forum.