As long as you see it as just a payment network, or a financial protocol you will have trouble seeing it's true potential. It is a protocol that enables digital scarcity in a decentralized manner without the need for trust. It allows for hard promises. After a few blocks a transaction is effectively irreversible. So it has to be extremely expensive to 'overwrite history'. I mean overwhelmingly expensive. It's a feature, not a bug.
Will this scale to the entire population. Of course not! Nobody is saying it will not change and evolve. The current implementation is great for a settlement layer while the LN would be used as a payment network.
We have been running out of IPv4 addresses for the last 30+ years, but things still work. People have been hard at work and incrementally IP was able to handle more and more devices (Address Classes, Classless Inter-Domain Routing, NAT, ...).
You praise the blockchain technology in general

Bitcoin doesn't equal the blockchain technology. I see that the blockchain technology isn't dependent on bitcoin and bitcoin value isn't guaranteed by the blockchain technology.
I think that you are bringing forward first mover advantage with the e-mail comparison. That the e-mail protocols mostly remained the same and this will probably make bitcoin remain dominant also.
I think e-mail can't be compared because of the simple nature of the problem they were solving. You can't exactly re-invent something as simplistic as a wheel. This new field of cryptos or financial protocols are a lot more complex and can improved a lot by re-inventive improvement. We have seen radical development with new generation cryptos in terms of speed, costs and practical usability.
@Jacques_Bittard please post your BTC address.