Because of having new technology is one of the reason why bitcoin is created. Since bitcoin is created then many people find a way to make use of it like an exchange where they earn profit from their users buying and selling, using crypto as one of the payments available in their casino and many more. Maybe there will be something what will be created with AI then use bitcoin as one of the many mode of payment that will be accepted.
If you mention trading and payment methods are the reasons for one of the forms of modern technology from Bitcoin, that is not wrong ... however, the characteristic of Bitcoin that makes it more modern and interesting is decentralized ... there are no banks associated with transactions on the Bitcoin blockchain, so there is a better level of privacy making Bitcoin more powerful and different from other technologies ....
Trading ?? we can use stocks and the way it works is not much different, but because Bitcoin is decentralized and stocks are centralized, that's where the difference is ....
Payment methods ?? paypal and bank transfers are currently more dominant, but because there are some people who prefer decentralization as a good feature, Bitcoin is considered a better payment method.