You are right that Bitcoin main technology does not need internet. Internet is just fast way for it to communicate. Core of Bitcoin is math problem that can be solved offline. Some projects like Blockstream Satellite are already building way for Bitcoin to work without internet by using satellites to send information. This would be big help in places with bad internet or during outage. However whether this system becomes widely used depends on if governments will allow it. Since independent network could let people get around censorship and government control it could lead to big fight between decentralized technology and power of governments.
Yes, you’re right. Bitcoin can work properly even without the internet, and it will never completely off in the future. The internet is just a tool that improves our quality of life and speeds things up, but bitcoin doesn’t directly depend on internet. Bitcoin is driven by mathematical calculations. So, there are alternative ways to keep it running. Such as blockstream Satellite, radio technology, sneakernet and other similar satellite systems can transmit bitcoin data. Now all developed countries are already adopting bitcoin and electricity is rarely a problem.