But you posit that people choosing cigarettes provides some value, despite the negative effects. Why is there no value than in people being able to chose a money/investment vehicle they believe to be to their benefit?
Because the only thing generated is fake money on a spreadsheet. There is no product, there is only consumption of resources to generate nothing.
For all of what's involved here, you could just pull the same amount of money out of thin air, deposit it in their IRA, and nothing changes, apart from way, WAY less energy consumption.
Gold is one object that's served the money function in the past. It has properties (fungibility, durability, scarcity, etc.) that money needs. But it's "dumb" and cumbersome, as physical objects are.
Building digital objects that serve the money function is important. One solution is the centralized ACH/banking system. But this has drawbacks --- poor scarcity, high political exposure, etc. I view BTC as simply building a competitor. You get better money properties, at the cost of more energy, etc.
Is it worth it? I don't know. But that partly depends on how the future produces energy.
If bitcoin went away tomorrow, a bunch of financial companies would have a lot of problems, a few big holders would be out money, and that's it. For every other human, it's Thursday.
Conversely, if gasoline didn't exist tomorrow, society would collapse.