Your offline purchases are usually outside the scope of blockchain analysis, so you don’t have much to worry about there, but then again your credit company has that data, which is why privacy conscious people might prefer using cash due to its fungibility.
I got your point, but dude you won't believe we (means me) are living in the stone age, we don't have the luxury to do online buying here, I can do online shopping from bigger cities but can't do in my nearest city. The point is all of my purchases are offline, I do p2p and convert my funds into fiat and then use them offline. No trace of online shopping left. Although I don't like online shopping. Speaking of credit cards, I don't have it, I hate it. As I don't like the way it works, they make you more spend, take borrow, pay interest, etc. etc. That's why even if I could have the facility to get a credit card in my area, but wouldn't have the facility to use it everywhere but in few shops only.
I would still not have it. That's why I don't care about privacy, the point here is, what other factors are there that we should keep in mind while acquiring anonymity, besides the fact that your government banned crypto in your country, and online sites can use data for showing ads. I would love to hear more.