Even if you are good with your finances, they are still more expensive and if you use some kind of bookkeeping or budgeting software, you will have issues connecting the export.
Yes, I know of cashback, but those don't exist everywhere and exist so you buy more to fund the consumerism going on. Which is actively hurting society.
The insurance part is nice, but often it's not better than what you get with a normal bank card.
Creditcards in most countries will hurt your credt score because of if you are paying money to pay off a credit card you cannot use that money to pay for your mortgage.
There is also that technical benefit of having to pay later which means you can "invest" that money, but for the average joe that is an irrelevant benefit.
The only benefit to me of having one is that I can use them on American sites that don't support other payment platforms which is most American sites (including Amazon.com, while the European brands do support Wero etc.)
You might be able to handle the responsibility of the credit card, but a lot of people don't.
You still won't be able to pay on the majority of American sites, since they lack a proper payment platform.