1) North America has lots of this kind of energy. Gigawatts/hr being spewed into the atmosphere as an unprofitable waste byproduct as is.

2) Transporting this energy is a cost. Storing and then transporting the energy is a cost. And other kinds of computation on site requires much greater infrastructure, like internet and big box data centers, which these remote sites do not have. Bitcoin mining barely needs any internet bandwidth and doesn't need a low latency connection either. It creates an asset that can be easily sold to people willing to buy that asset at a price far greater than the costs to create it.

Its important to understand that these are partnerships between two companies.

The existing energy producer who is taking a risk on a dangerous operation, largely technophobic and takes far too long to understand how it benefits them. And a separate crypto mining company searching for cheap energy, driven purely by the market.

The mining company sees the energy. The energy producer needs to reduce their waste byproducts.

Its semantics and pure coincidence about whether “less hydrocarbons billowing directly into the atmosphere” meets your criteria for “carbon offset” or “green energy”, its also what happens