I will humbly asset that nowhere does anyone convert money for free... They always charge somewhere or have some motive. The old saying us that if a produyis free, then you are the product. It is better to have an open clear fee with an honest transaction.
Many of us are used to 'free' banking but it was only free because they want our deposits so they could loan out ten times the money and sell us credit cards and loans.
Fair enough! I don’t mind paying a fee as long as there is an easy way to convert Satoshi to fiat
The fiat on and off ramps (centralized exchanges) are regulated and partnered up with regulated banks and they are all forced to kyc the shit out of anyone converting between the two currencies, and they charge fees.
What you seemed to essentially be seeking is a free peer to peer mode of fiat to bitcoin conversion or vice versa, which is a p2p exchange like robosats, but still that usually involves an institution/company for the fiat side of the deal (because fiat is slavery/control money and sending value over the internet is core to what bitcoin solves). Plus there is generally a premium for those offers anyway, but at least it goes to the person directly.
The other mode would be a physical cash exchange in meatspace. Obvious cons include probably a premium, few opportunities, and some risk of physical danger
