Yeah it shouldn't be an excuse. Sure the billionaires are terrible per person compared to a regular person. But they are still a minority. Most of the air traffic is regular folk traveling for work or fun. And freight being hauled by plane or trucks because of all the useless stuff people buy. Most of the cars driving every day are regular folk. By far the worst thing are cruise ships, dumping out huge amounts of pollution just for people to go on holiday.

Billionaires are terrible and should not be allowed to exist as they do today. But it isn't a reason not to do something yourself. If enough people do it, it will make an impact.