I'd say the age of mass air travel didn't begin til the mid 60s and even then was out of reach for most people. AT&T launched it's mobile phone service in 1946 believe it or not. Car phone service in 48. Bell labs worked on the first cell mobiles in 47. The first Dynatac Bricks were 73 but they weren't mass market

Finland actually had a statewide digital currency in operation in the mid 90s called Avant, although it wasn't a blockchain more of a CBDC. I'd say mass market for crypto would be 2030 at the earliest with them becoming fully integrated into the internet 2040s. Mostly because I believe the currency aspect of crypto to be a dead end due to CBDCs being pushed onto the populace. Won't stop crypto being used a very liquid swappable asset though. I imagine that they will be used as a way to legally circumvent pigovian taxes, laws and patents. Eg. seed sales in agriculture, liquor taxes. Something that most people in the crypto arena haven't even cottoned onto yet.

Agree about the problems of converting crypto to cash. Revolut include the feature in their standard bank accounts but it's not well known. Bitrefil is a nice non-KYC way of getting round it.

Agree that producing BAD code can be quick :)