bitcoin mining is not profitable enough, if we look at the expenses made by miners, it could be said that bitcoin is not profitable enough, because electricity costs are expensive, people who do mining have to spend a lot of capital, sometimes the profits they get are not in accordance with their expenses .
If bitcoin wound't be profitable we would have nobody mining and the blockchain would simply stop, but the reality is that we have a million mining gear up and running, which invalidates your 2 seconds of thought theory.
Your argument seems reasonable but consider the fact that the technology of devices is improving over time. Mining devices are more powerful, consume less electricity.
Irrelevant and it's not quite true, efficiency has grown but overall energy consumption has also gone up you can have 100 times more efficient gear tomorrow if the price doubles so will the energy consumption.
Renewable energy will also play a big part in the evolution of miners' equipment.
Nope, renewables are not reliable, not providing energy 24/7, and can't compete in costs with traditional fossils unless subsidized by the government.
The computational power is not a good metric to compare with the security of the network*, you will need to be looking at the costs of it.
That's probably the only real way to approximate the security of the network would be to look at the average price for the hashrate.
Just because the hash rate is 1000 times higher than what it was in 2014 doesn't mean that the network is secure 1000x, if we look at the average back then it would cost nearly $1k to get a TH out of S3s, not you can get it for under 100$. I would rather look at the security of the network from the reward per day perspective rather than the hashrate because at the end of the day it's the first that dictates the latter.
As for the stabilizing part, in the long run, I think energy prices will matter more than asic prices, and the future doesn't look good at all.