Because bitcoin is the king of cryptocurrency.
It has great value.
Bitcoin can be exchanged for a large number of legal tender.
Bitcoin is the king of crypto, but every bitcoin deal is not legal. Many people have given up bitcoin because their country prohibits Bitcoin and all transactions are considered illegal.
No one want to give up on bitcoin because now it is not hard to know that bitcoin has bright future people are agree to invest more and more so bitcoin price will rise with each investment. Bitcoin is not only the currency that people will buy and use but it is also an investment that will give you benefit and bright future. Bitcoin can make earn money even without investment that is using bitcoin signature campaign.