I'll take basically any USD-denominated bet that says Bitcoin will never be more than 5% of real-world transactions by volume in any country in the world.
You make the typical mistake of looking at current problems and failing to envision solutions. Like people considered early 19th century automobiles ("This will never work! These machines are too noisy. They keep breaking. Roads are not smooth enough. There are no convenient gas stations.").
Humans are good at finding solutions to technical problems. It was already demonstrated a quad core CPU and 8Mbit/s of bandwidth are already sufficient to support scaling to at least 2000 tps. The problem is people don't agree how to allow this to happen (Lightning network, or block size increase, etc). But that too will eventually be resolved :)
The reason you will lose that bet is the "any country". In some less developed countries, inflation is out of control (govt sees money printing as the only solution) bitcoin as measured against their currency is rising. Daily. Couple that with the fact that those same places do ironically have high mobile phone usage, and it's only a matter of time until it's surpassed 5%.
If Bitcoin was 5% of transaction volume it would be an amazing success. Even a 2% (assuming a country with a medium sized economy) would be massively game changing. I believe 2% transaction share is at least possible in the next tens years.
