Although I'm not new to the fact that all transaction have to be spent in a single output buy why does it have to work that way??
~Snipped
The way that Bitcoin transactions work is by design. It's not the same with every other blockchain networks so we just have to understand and accept it because if you try to take part in governance and try to change things, it's a really lengthy and tiring process that might take years to be deliberated on and implemented. That said, anything that is returned is called an unspent transaction output until you get to spend it by sending it to another address.