You’re dead wrong.
Have you ever heard of Bitcoin mining farms? Their electric energy consumption dwarfs a league of mainframes.
Am IBM Z16 may need several dozen kW at full load: https://www.ibm.com/docs/en/systems-hardware/zsystems/Z16M-A01?topic=requirements-general-electrical-power
Fully equipped with 8 PDUs and 4 BPAs a single mainframe is limited to an electric power of 173 kW.

Well, the Bitcoin miners are estimated to use around 175 TWh of energy annually, which equals an electric power of around 20 GW : https://www.statista.com/statistics/881472/worldwide-bitcoin-energy-consumption/
This is several orders of magnitude above that of all the mainframes in the world - unless there are more than 116 million mainframes of that type in operation and running at full load.

But unless you use Monero or other crypto with similarly strong privacy all you do is leave a permanent trail for agencies to investigate.
Using shell companies on the Cayman Islands might be the safer approach.

…and the hate is strong.

I agree that scaling power comsumption is unsustainable - both ecologically and ecoomically!
But power consumption is no inherent attribute of crypto, but a design choice.
Bitcoin just refuses to adjust.
Ethereum did that not very long ago.

What I’m trying to say is: there are designs available that operate at a very tiny power consumption.
Don’t lump all crypto together with Bitcoin.

XRP is fast, but neither instant (usually around 4 seconds) nor without fees:
https://xrpl.org/docs/concepts/transactions/transaction-cost

The cherry on top is the skewed token distribution.
Thanks, but no thanks!

All of what you say applies to most cryptocurrencies.
But I’m aware of at least one digital currency that is

• without fees
• usually confirmed in less than one second
• eco-friendly because it requires no special hardware to operate the network and it uses very little energy

It has also zero inflation, is decentralized and designed with incentives that increase the degree of decentralization over time.
It also has no built-in limits regarding transactions per second.

Consumer protection without middlemen/centralization is hardly possible.

I’m hesitant to drop a name here, because I don’t want to come across as a shill, but if you’re interested we can discuss the attributes of this gem.

edit: ah, the good old “I don’t like what I see, but I have no arguments, so I just downvote without engaging” approach. Or does it just sound too good to be true?
You know what, I’ve changed my mind: https://nano.org/en

Sure!
I was merely trying to raise awareness for the need to bring privacy protection to a level beyond E2EE, although E2EE is a very important and useful step.

Yes, like Signal!
Which does not only use end-to-end encryption for communication, but protects meta data as well:

Signal also uses our metadata encryption technology to protect intimate information about who is communicating with whom—we don’t know who is sending you messages, and we don’t have access to your address book or profile information. We believe that the inability to monetize encrypted data is one of the reasons that strong end-to-end encryption technology has not been widely deployed across the commercial tech industry.

Source: https://signal.org/blog/signal-is-expensive/

I haven’t verified that claim investigating the source code, but I’m positive others have.

Signal doesn’t harvest, use, sell meta data, Google may do that.
E2E encryption doesn’t protect from that.
Signal is orders of magnitude more trustworthy than Google in that regard.