I know that Bitcoin has become more known and trusted by many people but I still see many popular websites don't accept bitcoin like amazon. I'm only seeing bitcoin is mostly used for illicit activites or as an investment. Why Bitcoin isn't adopted yet in most legimate websites?
bitcoin is a currency so you can buy anything with it but is bitcoin legal in your country? I'm Indonesian and until now bitcoin is still not allowed to be used as a means of payment, so we usually use bitcoin as a hidden transaction. I just used bitcoin once as a transaction that was when I bought a new GPU for my computer luckily the shop owner accepted bitcoin.
It is a currency but unlike to a common currency, btc has some restrictions (country and website restriction) the op's concern is more on the online and not locally. Most computer sellers know something about btc because btc is related on the field they are working with but courage is still needed to do a transaction in your country because btc there is considered to be not so legal. How about accessing to a btc/crypto site, is it allowed in your country? or if not, you can use a vpn and buy stuffs there online using your btc.
As of now, btc popularity have gone through the roof so I'm expecting that lots of websites now accepts bitcoin and other crypto payments.