Are you a serious blogger? Then you need some kind of payment processor. A lot of people use PayPal. Other systems, it's really crucial to have payment processor of some kind.
Because sooner or later, if you are a serious blogger and if you are in blogging world for a long time with long term goals, you might want to have a possibility to collect money from people.
Money in form of payments, subscriptions, or even donations if you don't care about producing paid type of content but that works, too. Because your work is valuable to people, your time is valuable and you produce great information. You help people, that's the main idea of the blog that you have in mind.
Sooner or later, people will have to reciprocate. People will want to say thanks to you and there are a lot of ways to say thanks, right? In sharing your information, spreading the word for you, posting on social media about you. Basically become a mega phone of your work and become your true friends.
A smaller amount of people, a smaller group of your readership will really want to work closer with you. Because they want your personal attention, perhaps. They like so much your free information that you're providing on your blog, that perhaps they want to buy something from you and they will ask you for this.
Actually, to have a form of payment, to pick payments online is really a must at some point. PayPal of course is one of the primary ways to do this.