As right now BTC is more of a store of value. The value of it is not high enough to be able to use mainstream for the global market as the money system. For all markets to be based on.
Do you think that if ever there becomes more adoption, BTC would be and able to be used for mainstream like a global money? Does the tech work enough that it could handle the global market?
why or why not?
First, Bitcoin has to be accepted by everyone in the global market or in every part of the world before it can be used as a global money system in every market. Apart from El Salvador, where Bitcoin is legal tender, and any other country that treats Bitcoin like a legal tender, every other part of the world doesn't treat Bitcoin as a legal tender, and therefore those people that accept Bitcoin in those places do so under a per-to-per agreement before the payment can be carried out. For example, Bitcoin may not be banned in my country, but you cannot go to any random shop and ask to pay them with Bitcoin; they won't even attend to you.
Unless the government has deep control over everyone who is using Bitcoin, it cannot be generally used in the global market as a money system. Before that can happen, countries that have banned Bitcoin have to lift their ban; people who don't accept Bitcoin have to do so at will or out of will, etc. Bitcoin was not created to force anyone to use it, (it was supposed to be, every individual to their personal decisions and dealings with their Bitcoin).
In our imagination, let us assume that Bitcoin has become the global money used in the market all around the world. You asked if the technology was enough to handle the global market (?).
Definitely yes! But people will have to deal with a high transaction fee because the mempool is going to be very congested with different businesses and customers sending in trillions of transactions in seconds. Of course, there have to be more miners to handle the world's (population) Bitcoin transactions.