Worldwide, the percentage is similar.
Of course being unbanked isn’t equivalent but it’s likely very nearly so.
Not to mention, the chances of being unbanked are higher for vulnerable populations, especially those who might benefit from uncensorable money.
The last transaction fee I paid was 33¢, and the average transaction in the last Bitcoin block was 913 bytes, so your internet access speed isn't an obstacle to sending a transaction as long as it's above about 20 bits per second; if you want to run a full node you need at least 17000 bits per second of internet access unless you're using the Blockstream satellite.
Typically I pay US$5 a month for cellphone internet access when I have it, but more commonly I use Wi-Fi in various places.
The fact is that many people hold their wealth in cash, and many of the same people are part of vulnerable populations.
One shouldn’t remove another’s alternatives simply because it’s assumed that the other lacks access or sophistication. Even if true, both potential deficiencies are fully reparable and do not permanently negate the benefits of uncensorable money.
Centralized internet is not long for this world. The Internet is being fractured, both ideologically and physically, right now, by world war.
This only gets worse before it gets better, which probably means mesh networks will be adopted soon enough. Anyway,
This is why adopting distribution of responsibilities is so important in projects like Ethereum — your offline handhelds will be able to make provable transactions without having immediate communication with every star in the constellation, so to speak.