Im just happy no bank gave me a credit card in my 20s i was a massive idiot. Now early 30s never had a credit card and learned to be frugal.
Credit cards for daily purchases are the way to go. They offer an added layer of security over debit cards and you honestly get better rewards for using them. Pay off your balances before your statement comes and you will get a health dose of cash back rewards and boost your credit for when you need a loan to buy a house.
Even if you don't care about your credit score, they are still far superior to debit cards if you get something with 2+% cash back or with price protection benefits.
The added layer of security shouldn't be underestimated. If somebody gets a hold of your debit card info and runs up a bunch of unauthorized charges, it's a massive headache to deal with your bank and your account will most likely get frozen while they resolve the issue. If somebody gets a hold of your credit card info, it's pretty easy to dispute the charges with the credit company, easy to cancel the card and request a new one, and you don't have to deal with your bank account being frozen. It's honestly a no brainer.
I'll also suggest that you should have multiple cards. Should have something that gives a flat 2% back on every purchase, then get a couple more based on spending habits. Some cards offer 5% rewards on rotating categories every quarter. Might be restaurants one quarter, gas stations another quarter, I've had target/Amazon 5% back during Christmas season the last 3 years (which is pretty damn nice for Christmas shopping), etc. you can find cards that will give a straight 5% back on grocery purchases...hell Bilt has a MasterCard that lets you make rent payments with it that gives you bonus points for that.
I understand not wanting a credit card if you don't trust yourself, but if you have taught yourself good habits, you'll still have zero debt at the end of the month!
Edit: Also, for cards that offer points or cash back, you can often choose to spend them at checkout at the card terminal. Don't ever choose that option! Most credit card companies will do some funky math and reduce the value of your points if you don't choose a straight cash deposit into your account. It's different with every company.