If McDonalds accept bitcoins for our favorite meals, How are we supposed to pay them? through blockchain wallet? or are there other ways too?
It's simple, you scan their QR code with your smartphone, and then approve the transaction, and it's done. It can be done with basically any proper mobile wallet client, so you don't necessarily need to use an online wallet app for that. You could also choose to "spend" Bitcoin through a Bitcoin related debit card, but these just convert it to fiat, and then settle the transaction in fiat. It's not actually paying with Bitcoin.
Nice right! we won't have to carry our wallets with us. All we need is a mobile phone.
It's nice if you can buy your burgers and french fries without paying 50% of the initial transaction value in fees. I just use the NFC field of every merchant in my local area to pay with my bank card, and it's done. No fees involved, it offers ultimate convenience, I enjoy buyers protection, etc. The incentive to spend Bitcoin isn't there for me.