There isn't much benefit to having them though, other than pure convenience.
This point is not true.
Doc suggested travellers checks, but those cost way more than my credit did, because as Shadow points out, holding a card with a grace period (wouldn't touch any other kind, thank you very much) means the loan can be paid off immediately, at zero interest, for the cost of a stamp and the time to fill out the bill. To carry travellers cheques would have cost me more in both time and money, plus the hassle and time of refunding the unused portions after the fact. There is no way no how that that would have been a better solution for me.
Credit card companies charge a transaction fee (about 3%) to all merchants doing business with them. The merchants have little choice. Those who won't do business with credit card holders in today's economy are closing off way too many potential customers. The card companies MAKE A PROFIT even when you pay off your bill immediately, with no interest accumulated. (Did anybody here not know this?) That they charge often exorbitant interest, fees, etc, for those rack up balances, is another issue, tied to credit responsibility, not the worth of credit itself.
Should I be carrying a wad of current travellers cheques every time I step outside my front door? No way am I going to do that. Too much time, money, hassle, waste. I can carry far more emergency ass-saving financial potential in my wallet, with plastic, at NO CHARGE TO ME, and at virtually no risk. The risk lies in whether or not I will abuse the credit, but I don't so there is no risk.
I've also gotten into situations where I wanted or needed money on hand, that were just as much surprise as the car accident at Niagara -- and which have taken place just a few miles from home. You simply can't have it both ways with cash: it's a hassle and a risk to carry it. Period. Less risk but more cost and more hassle to carry travellers cheques, and what? Going to do that every second of every day? Going without cash would mean going without purchasing power. Sure, you can, but there are times you may (or will) get stuck in a pickle without enough cash, or get stuck in a worse pickle with too much cash! You can carry cards in your wallet and have the best of all worlds, with enough purchase power to cover any contingency or to take advantage of any unexpected opportunity.
That's another key point in credit's favor: the chance to seize on unanticipated opportunities. Maybe it's been a while for Doc... but I've been out and about my normal business and met an interesting woman, or bumped into an old friend, and not been carrying a money clip. Credit has enabled me to enjoy some great times, which I would otherwise have had to pass on -- and which I could well afford! Or... I pass a sale and make an impulse purchase on a great deal. (Now that starts to sound dangerous, but for it's NOT. I don't ever lose control of my spending). Or... I may go out with the intent to purchase products X and Y, and get there and find Z is also available, and want to buy it, too -- or buy it INSTEAD. Either way, it goes beyond convenience.
Getting caught in an emergency without enough funds to dig yourself out goes beyond convenience, too. If I had to wait in Buffalo overnight, I'd have incurred all sorts of extra expenses: motel, food, phone calls, who knows. Might also have put my security at some risk. For what? Too scared of my own shadow to carry a credit card?
Doc's making no separation between credit abuse and credit itself. He seems a little obsessive about that, but my experiences involve only good things about credit.
It's more than convenience, though.
If you don't have credit, you can't do business with certain kinds of merchants. Can't order stuff online from many places, for example, but that's just the start of this phenomenon. Also, credit card companies will go to bat for you in disputes with merchants, which can save you time, hassle, and/or money. What would Doc's solution to that be? I imagine him saying, "Don't do business with those merchants then!" Fooey. I pay my balances off immediately, there is no charge. I get convenience, security, reliability, peace of mind in many forms, and my life is made more pleasant and hassle-free in a variety of ways. And the funniest part is, the credit cards DO make money off me anyway -- and are HAPPY to do it, because I'm a reliable customer. They don't worry about me defaulting and leaving them stuck with a loss. They surely DO charge exorbitant fees and interest to the degree they can, but a certain amount of that is actually justifiable based on their default rate, and losses that go down the tubes on bad loans or settled accounts. Then again, they have more of those because their standards on who they will loan to are low. None of that is my direct concern. I make credit work for me, and it has been nothing but a blessing at every turn precisely for that reason.
For Doc to continue to insist that credit is the devil and could never be a best choice for anybody... what can I say? My views and experiences differ.