My parents believed that the only debt should be a home mortgage. They had store credit cards, but paid them off every month. I have never had a credit card in my name, they were always in my ex's name, with me as a secondary name. I get offers every week. They get tossed in the trash.
Good credit can be a tool to the accumlation of wealth if one knows how to properly employ it. Likewise with debt. When managed cleverly debt can also build wealth. Example; investment properties that service their own debt and are then leveraged to acquire additional investment properties that in turn service their own debt.
There's nothing wrong with credit cards per se, just pay them off every month. Get the right ones and you can get cash back or other bonuses. I get 1% back on everything, and 5% on gas which is especially useful these days.
You could be a sibling of mine! My parents have always lived the same way - no debt except a mortgage, and pay that off as soon as possible. Don't use a credit card unless you can pay the balance in full within a month. My dad's retiring at the end of this year with virtually no debt.