I use it to donate or pay for legal things online I wish to keep anonymous like I would use cash for in person. Most people in the US do not value privacy, but for those few of us that want to purchase online with privacy, or those in heavily censored countries, cryptocurrency is the only option.
Just because few people make use of their rights is not a valid argument for their removal.
I would never use BTC purchased directly from an exchange to make anonymous payments. If a vendor only accepts BTC and I want privacy I normally swap it for monero then back for BTC again to remove any connection to me.
Just because few people make use of their rights is not a valid argument for their removal.