If I could only use crayons on the screen you might understand.
"Online Free Trials" -- not "buying something" as you misunderstand... but an offer to "try us free for 14 days"... but they make you give the credit card information up front so that after the 14 days they can automatically charge you for a subscription "for your convenience" rather than you having to initiate the activation after the trial.
It's not for the customer's convenience, it's for theirs. They hope you'll forget and they'll bill you and you won't protest.
So the "for your convenience" part IS A LIE JUST LIKE the "for your health" part of wearing masks. It's not for the person's health, that's their own choice. It's for the sating of you whiners who want to make everyone conform to your way of thinking in spite of all the science to the contrary or to cover their butt from liberals suing them later for some silly reason.
Now if you don't understand it after this, seek a fourth grader to explain it to you -- it's really that simple. Sheesh.