By this logic gold would be just as bad. Where was the push back against gold? what is gold backed by? If Bitcoin is centralized because of it's mining requiring expensive investments then why isn't gold?

See this is the mentality that fooled people into basically giving away their valuable gold in exchange for worthless fiat. Fiat will crash once the depopulation starts for real, it's designed to only work during constant growth but has no mechanism to handle mass deaths. Cash will fall with it too because it's the same scam, just a paper version.

They will make their own digital currency, probably running on a blockchain, why shouldn't they? it's the best technology available for the purpose. It'll have mas surveillance, expiry time, centralized key management and other crap, but hey at least it scales and fees are low, because of centralization (government does all validation/mining).

This is how they trick you into it, convenience. Do your research or risk getting fucked over. What sense does it make for them to reinvent digital currency (technology they already have) but in the shape of wealth that cannot be censored, surveilled or confiscated. That's the last thing they want. And this only because they need better back-end technology? Nah, that's just stupid, if it was "training" they would have developed and tested the system secretly and never released it as open source.

If the government has any involvement at all it's more like TOR, you know the anonymity network created by NSA, but still is proven safe to use.