but it can replace the current internet payment systems, instead of paying with credit card over the internet that will also require you to reveal your credit card details, you can play anonymously with bitcoin.
I highly doubt that. People nowadays are too dependent on credit to sustain themselves, so the fiat related payment infrastructure will remain pretty much for ever and beyond, thanks to this shitty system.
Also, in order to spend Bitcoin, you have to buy it first, and let that buying happen through centralized services, which basically means that the anonymity you're referring to doesn't exist.
Mixing could be an option, but mixing services are still a niche in current days, and as long as that doesn't change, people will not be able to obtain even a remote form of anonymity. Blockchain = big brother is watching you.
I think this is quite reasonable. because many online service companies will compete for digital money services as an easy and instant money exchange tool. So it forces many countries to learn to provide legal clarity to protect the online companies of every country.