You are very defensive Toastytoes1, and also rather naïve.
I've done mine on the way to the airport before. What does it matter?
Because it covers the cost of your holiday if you have to cancel before you go. My friend was going on a long haul holiday and stayed with her mum the night before. Her mum died during the night so she didn’t go. Her travel insurance paid out for that.
Another time, she had appendicitis on a cruise and had to be taken off the ship to the local hospital to have her appendix out. The travel insurance paid for her treatment, her husband to stay and her flights home. An EHIC card wouldn’t have covered half of that.
I’m with the OP in being bewildered by the naivety of people who leave getting travel insurance to the last minute or don’t bother getting it at all. Clearly people don’t seem to understand that travel insurance also covers you if you have to cancel the holiday. This is why it is important to take out the insurance at the time of booking. Obviously, there are exceptions, especially those who have complicated health conditions where travel insurance can run into four figures, but for most people travel insurance isn’t expensive at all.
We have an annual policy with our bank account, so at least it isn’t something we can forget.