Re: Ordinals and other non-monetary "use cases" as miner reward on 2140+
There is also an additional point. Bitcoin mining companies are basically server farms. In periods of low profitability, they can diversify their income sources offering servers for other cloud services. This is already been done by most big mining companies, and it is also one of my reasons why I think that if profitability drops there will not be a "big hashrate crunch", but a very gradual process, because bigger miners will slowly dedicate more percentage of their farms to other cloud services once their hardware becomes unprofitable, instead of going offline completely. And that will re-balance with difficulty growth again and again.
Bitcoin mining companies have farms of ASIC miners which are designed to only do one job, to mine Bitcoin. How can they offer other cloud services? If they had GPU mining farms (which isn't profitable and as far as I know, everyone is on ASICs), then they would be able to rent their GPUs to AI labs and anyone who wants to use it for AI.IIRC, what you're suggesting is already a reality in Texas. Miners there don't work 24/7/365, but only when the state has a surplus of energy.
Yes, it's beginning, but I think it's still a 95-99%-on model. AFAIK those miners only turn off the gears in periods of extreme demand surplus, when they're "ordered" to turn off operations by the electricity distributor, as a condition to benefit from energy credits (Riot case).But why would anyone who feels threatened by Bitcoin spend twice the wage of the CEO of JP Morgan on killing it.... 
No one is going to attack Bitcoin. Simply it doesn't worth and is completely meaningless. In fact, it would be one of the dumbest thing that humans could ever possibly do. What if they attack the Bitcoin network? The code is here, there are countless number of altcoins, if Bitcoin falls, another coin rises and I don't believe someone is going to spend billions of dollars every time a coin is created. Also, too many serious companies are involved in adopting and integration of Bitcoin and too much money is put into it, we talk about trillion.