Nope. Usually it's us US-ians who change things for no good reason, but in this case it's the Europeans. I actually looked into this at one point, when I was curious to learn who thought it was a good idea to use the comma as a decimal point. It's a relatively modern change. What I wasn't able to discover was the reason behind the change.
This isn't a question of some old farts from the 1960s who refuse to switch from cycles per second to Hertz. It's literally the sort of thing that shows up in case studies after a bunch of people get killed. Unnecessary changes like this need to be fought, and fought hard.
I'm not certain what you mean by this. The decimal comma has been used at least since the 19th century in continental Europe, but Britain favoured the point.
You reference to "modern change" must refer to computer technology, where the comma at some point was used to delimit lists, options and variables and as such could cause problems with numbers.
That being said, I have two preferred options for presenting large numbers:
10.000 000 000 5 (US/UK) or 10,000 000 000 5 (EU). This one is not my 1st favourite, as it can present problems in formating.
10.000'000'000'5 (US/UK) or 10,000'000'000'5 (EU). I like it,as it's practically impossible to misinterpret and easy to read.
In both cases, adding two zeros at the end would add to aesthetics.
But everyone has his/her own style, I find clarity most important, speaking as an engineer.