What are the chances bitcoin big mining pools to unite and do 51% attack? Looking at this bitcoin hash rate distribution chart (https://www.blockchain.com/en/pools), it only takes 3-4 mining pools to unite and do a 51% attack.

With this possibility, how can people still think that Bitcoin can be the money of the future?

PS: I'm also a bitcoin believer
It won't happen if the bosses of the pools are all ideal.

In the real word, they may be lunatics or terrorists, they may be cheated or threatened. As long as they have the ability, the world is in danger.

The traditional security is based on economics, or on rational persons. That is not enough. The goal of cryptocurrencies is to upgrade the security to be based on cryptography.

To consider security like "they can but they won't" is no more than the traditional system, cannot reflect the superiority of cryptocurrencies.