The whole blockchain is now very long... it will require little bit more computational resources than just 51%.
Who knows... every now and then new supercomputers are being created with massive computational power. Will create interesting scenarios in the future.
but the current network is only being strengthed ,not weakened as btc becomes more famous
its already bigger than anything anyone could attack it with and its growing with every new bitcoiner who joins
and gpus and asics are sold out everywhere
nobody is going to invent a supercomputer anytime soon that can outperform the btc network