Merchant always honor buyers payment method .. for example they accept credit cards though there is 2 percent fees ...to give me 1 percent cashback :-)

That's because you have market power. You're buying low quality, mass produced, interchangeable widgets. There are things where the merchant commands market power. Anything unique, high quality, difficult to replace, bleeding edge - in those cases, the one who has the thing has power. Bitcoin shifts that back - since it is scarce, it can buy scarce things. Holding bitcoin is pure power. The merchants that aren't dipshits will do anything to get it.