If someone discovers a free, unlimited energy source, launching a 51% attack would be just a matter of seconds. And that is exactly what has happened.
Bitcoin mining relies only on electrical energy source, there can be free energy sorcees but these energies have to be converted to electrical which will take processes that will require money. And if it requires no money, it has nothing on bitcoin blockchain as it will be used to still defend it by people that mines, it will only be the best alternatives than wasting money on electricity payments but yet individuals will still have their mining hardwares running at low cost to generate more hash rates that will protect bitcoin blockchain.
With the right resources, anyone can easily utilize this unlimited energy to launch a 51% attack on the Bitcoin network. The cost of launching such attack would be incredibly low.
You are completely wrong, bitcoin blockchain is the strongest and now obvious in a way it is not vulnerable to 51% attack and the hashes generated is still increasing and making the blockchain stronger.
PoW is a failure. PoS is a better system. With Ethereum 2.0, Ethereum is slowing moving to PoS. The threat of someone having massive amount of electrical power is eliminated in a PoS system. As soon as the news breaks out, Bitcoin price will plummet. PoS and Ethereum 2.0 is the future.
You have no point to proof and you know nothing about 51% attack. Are you comparing Ethereum 2.0 to bitcoin PoW, bitcoin blockchain is much more and more stronger than ethereum blockchain. Ethereum 2.0 PoS can be good, but it is proof of stupidity if you are comparing it to PoW. Bitcoin blockchain is also the strongest of all.
Bitcoin blockchain remains strongest not because miners pay for electricity, it is because they mine to make profit while it happened in a way attackers already know bitcoin blockchain can not be compromised as the attackers hashes are not significant to what legit miners are generating.