What's new? These attacks aren't new for Bitcoin. But still, Bitcoin stands strong. It's not possible to move Bitcoin from PoW to PoS. Bitcoin isn't like Ethereum. Because Ethereum has a team who are deciding things and controlling everything as well. But Bitcoin doesn't have a team and miners have to decide. Do you think miners will ever support PoS? I don't think so since they are going to affect it in the first place. Just forget about technical things or how secure PoW is. Miners will never support PoS for Bitcoin.
And the real problem to convert BTC to PoS does not lie in the miners, as they’re just services providers to the nodes (they owners). BTC belongs to anyone or less say, it belongs to everyone who decide to install a full BTC node. It is not possible to move from PoW as it would hamper single normal people to own the very source of their wealth: running a full BTC node. Full stop.
PoW is one of the greatest inventions of history. PoS is nothing but the same BS running every single fiat currency, company stock, and so on. There’s no such an invention in PoS. It is just an euphemism for same old legacy BS that’s been running for ages.