I've never relied on CC insurance, always taken out a Travel Insurance policy. I used to use CoverMore, but they've got a bit term-crazy and expensive post Covid, so now I look at GO and NIB. I get mine through my Travel Agent - it doesn't cost any more than on-line for the likes of GO and NIB. My TA gets all the quotes, after I choose level of coverage (eg how much they will pay out in event of total cancellation) and excess (lower $ excess, higher premium), and then I choose & pay.

Many insurers have levels of policy - from 'basic/essentials' through to 'comprehensive'. I always choose comprehensive.
All the policies I've seen treat USA as a special case. If you aren't going to USA, then you choose one of the 'non USA' ones and its cheaper. But I think you MUST have good insurance for travelling in the USA.
Any cruise needs to be specified and will bump the cost up. Obviously 'dangerous' sports as well - snowboarding, etc.
You can get Single Trip (usually max of 45 days) or Annual Multi Trip.
A good point to consider is that the earlier you buy the insurance before a trip, the more expensive it will be, because the risk (to them) of cancellation is higher. I just had a policy for a cruise in December priced now (say, $1,500 premium) and same thing priced as if it started in a month from now (say, $500).
I'm taking 3 o'seas trips of 10 to 40 days in the next 12 months and its going to be cheaper for me to buy 3 single trip policies than the annual multi, which really surprised me. I think its because of the Dec cruise, which is 1) expensive and 2) a long way off, so cancellation risk high.
Covid covers differ between Insurers & some you need to buy, say 3 weeks before departure to get coverage. That may be changing though.
Some policies treat pre-existing medical conditions (such as diabetes, high blood pressure, coronary heat disease etc) differently. If you want coverage for 'pre existing conditions', you have to take a medical questionnaire on-line and it'll decide if 1) they will cover these or not, and 2) if yes, what the extra premium will be. I've given up trying to get coverage for a couple of mine, as I always fail the questionnaire, but I was pleasantly surprised that NIB, both in their "allowed pre-existing conditions" list AND their questionnaire, was more relaxed, and I got coverage for extra premium, which I decided was worth it.
EDIT: Check if and what the policy will pay out if you travel on rewards/points seats & have to cancel or re-arrange. Most will.
EDIT II: I wouldn't touch Qantas or any other 'third party' policy. Buy it direct from the insurer so, if you need to claim, its direct. Direct communication most important in an emergency - CoverMore, NIB etc have specialists on call 24/7.
Finally, READ the Product Disclosure Statements! Its a pain, but you must know what you are paying for and what won't be paid for.