People always told me I need to get one so I can have a good credit rating. For what? So I can pay more interest for a mortgage on a house I’ll never buy?

Credit gives you options. Furnace goes out way sooner than anticipated and you only have $5k in the bank? Take out a loan for the remaining $3-5k to get it done now. Unexpected car repair and you only have $500 after rent in the bank? Whip out the credit card and put the other $500-1000 on there and throw extra money at it until it's paid off. Yes you'll pay some interest, but you'll have a working car, or a working furnace, or whatever other calamity you find yourself facing.

But the biggest thing credit does it lets you buy property much much sooner in life. Property has a wierd habit of gaining value much faster than it should, the payment stays the same for the entire term of the loan, plus with a mortgage every payment buys you slightly more ownership of the property unlike a rent payment which is just money leaving your bank account every month for nothing other than the privilege of the roof over your head for the following month.

For a real world example, I bought my house a couple of years ago for ~120k. I live in a small town so I figured it wouldn't gain anything other than holding it's value through inflation. My monthly payment is ~800ish and similar places were renting for ~1k/month. Well thanks to the hyperinflation the last couple of years, my house is now worth closer to 180k and rents are up to $1200-1500/mo for a similar place to the one I own, but I still pay $800/mo for my house. That's what credit gets you in the long term. It gets you stability and options for when the going gets tough