I honestly think you shouldn't be able to complete the booking of a holiday out of this country, without putting in insurance details
Sounds sensible, but the trouble with that is that, unless you always have annual travel insurance, people will be pressured/compelled to take the airline or tour operator's insurance at the time of booking, possibly not at the best price or being able to make sure it is suitable depending on any pre-existing conditions or planned activities.
When you're trying to book flights that could get more expensive if you don't book now the last thing you want to have to do is read through the small print in travel insurance policies.
I agree with the principle that travel insurance should be 'compulsory' and you should get it as soon as you book your trip though. We currently have an annual policy, as we go away usually 3 times a year and we're borderline as to it being cheaper. From the numbers I've seen, if you go away twice, it's probably cheaper to get two single trip policies, but for three trips then annual will be about the same or cheaper.
But we’ve always had to pay a bit more than the often bargain basement prices quoted on here or on the likes of Moneysaving expert, eg £10 a for single trip to Europe or £20 for annual policies.
Our ‘standard’ holiday is a week in Europe for a 40 something couple and it’s always been more like £15 for a single trip or £35 for an annual policy and I do shop around, but I’m wary of taking the cheapest policy on the comparison site from a company I’ve never heard of.
And now that we scuba dive to depths that are slightly deeper than standard I'm extra cautious about making sure we're covered (most policies that include scuba diving allow to 30 metres and we can go to 35) and seeing as we all wear depth gauges, the insurance company will always be at liberty to ask for the data from the dive where any accident happened. Deeper than the limit on the policy = no payout.
The costs if we required a helicopter trip to a decompression chamber could be tens of thousands in certain countries and might not be covered on basic policies. Similar for ski-ing or other high risk winter sports. Always make sure it covers the exact sort of sport you will be doing and it covers things like helicopter rescue if needed.