While the Businesses of those 3 giant companies are just operating in limited jurisdictions.
But, we can still able to buy US's company stock even we're not an American, I'm not sure in your country, but in my country I can use local broker to buy US's company stock. Although it's true Bitcoin is more widely since no one can stop people to own Bitcoin.
It will be impossible for centralized bank to have higher market cap than Bitcoin because gradually fiat is depreciating and bitcoin value appreciates, which is giving people more confidence to invest in bitcoin and abandon fiat because of lack of confidence in fiat. Banks are run by individuals but bitcoin is decentralized.
If most people think like this, those three banks would be bankrupt or they have very low market cap.
I find this comparison lame and nothing worth celebrating. Why don't you try comparing bitcoin with corporations like Apple, Nvidia or Microsoft? All three of the above corporations are in the United States and if I remember correctly, all three have a capitalization of over $3 trillion, double the capitalization of bitcoin or even higher than the entire cryptocurrency market.
In my opinion, bitcoin is an asset, an investment, and for a fairer comparison we should compare bitcoin with gold and silver, not with companies and corporations.
As Odohu said, these interesting comparisons are only intended to strengthen people's faith in bitcoin and have no meaning. I will really celebrate if bitcoin's capitalization can surpass that of gold, that's something for us to be proud of.