disadvantages that i really feel it is if i have many bitcoin, and i want to spend it in real life i need to exchange it into my local currencies so i can use it offline, if i dont do that my bitcoin is useless, because bitcoin in my country is not popular than other country. and maybe the second disadvantages is the confirmations is slower than other cryptocurrencies like ethereum or doge
It is still long way for BTC to be accepted in all fields. In my country usually BTC is accepted in some cafes or some small shops. for the surprise our national airlines also accepting BTC as payment. other way to spend your BTC its good to use debit card services like cryptopay.