What about just paying the balance every month? 'Don't spend money that isn't in your pocket' seems pretty simple.
There are reasons to use a credit card - you get purchase protection, for one. You also can build up credit if you want to buy a house. You need one to rent a car.
But really, while there might be other reasons, the only reason to get a good credit rating is to be able to buy a house. Everything else can be paid for in cash (check, online payment from your checking account, etc)
When you use a credit card, you should treat it exactly like cash. You should have cash in the bank before you purchase anything with a credit card, and then pay the entire credit card balance each and every month.
If someone has a problem with this and just can't do it, then they should not get a credit card at all. Credit cards are very dangerous technology if one can't control it. Just like fire - if you are not careful with it, you can set your house on fire.
You can do everything you listed without an actual CC, including rent a vehicle (I know, because I do it).
https://www.fool.com/the-ascent/mortgages/how-to-buy-house-n...
And that's kind of the silliness of credit score, you can game it by never actually using credit.
I don't think you get the same purchase protection with a debit card vs credit card.
As far as renting a vehicle, I've tried on a debit card and been denied. But that was quite a while ago so things could have changed, and I guess have as you have done it.
As for renting a vehicle, their requirements are usually a bit more stringent, things such as showing more documentation that I live where I say I live, they'll put a hold on a larger amount, but I've never been outright denied from renting a vehicle for having a debit card.
Of course, having said that, I was denied the last time I tried to rent a vehicle because they had started running credit checks and I have no credit. This despite the fact that I had been renting regularly from them for 7 or 8 years (a few times a year). Can you imagine thinking credit was a better proxy than your own records for determining someone's trustworthiness?
I've never liked rental car companies, they're all shitty in 1 way or another, but that for me was the last straw. It will be a cold day in hell before I ever rent a vehicle again.
Instead I went out and purchased a vehicle to do exactly what I was trying to do with the rental, I posted about it here: https://news.ycombinator.com/item?id=34099429#34114741