In saying that, are you not ignoring the time value of money in your own life? To call paying interest "throwing money away" implies that you do not know of a way to deploy money in ways that add value. Therefore you would not pay anything to have it today, as opposed to five years from now.
The concept of interest exists because hardly anyone shares your preference curve in this regard. Most people place a higher value on a dollar today than they do on a dollar five years away. The market rate of interest is a measure of how much more value people place on 'money now' vs 'money then.'
Far too many find more value in "money now" vs. "money in the future." I was raised by savers, who lived modestly even when my dad was making six figures during the 1970s. Ironically, we managed to find pleasure in simple things, and always had more than enough money for the important things.
Then again, they were raised by savers, too, so much so that in their early 90s, there was still plenty of money left to pay a full time nurse $1,000 a week for a year and a half, with almost a half million left over when Grandma finally went home to God.
My best memories are not the expensive gifts I received, the jewelry, the weekend jaunts. My best memories are fishing in Grandpa's rickety old boat and eating peanut butter and homemade jelly sandwiches, taking old, garbage picked furniture and cleaning it up with my mother, helping my father turn a discarded tube television into a functional unit.
As for "having it today," when VCRs came out, they were nearly $1,000. We bought ours when it was $150.00. Same for computers. Same for a bunch of other things. Odd, is it not, that we managed to live without them until they came down in price.
My kids have the same "enjoy the simple things" philosophy, too. I can spend boatloads a money on expensive presents for them. What do they want to play with?
The box.