Agree with the sentiment - I also rarely see the value in a packaged account for one person. Having said that, I do open and close them on occasion (and have had a FlexPlus account open for the last few months) for a few reasons -
I tend to go on silly trips (marathons in the Arctic and adventure holidays and the like) and most travel insurers charge extra for those kind of activities, whereas packaged current accounts often have surprisingly thorough worldwide cover by default. So I’ll have a packaged current account open especially in years where I’m expecting to do more than one big trip.
They also tend to cover more pre-existing medical conditions (which just makes life easier if my asthma has been playing up as I don’t have to go through such an arduous screening process or pay extra for the privilege of taking multiple inhalers or additional medications).
Their mobile cover tends to have far higher limits than home insurance (my home insurance covers my mobile up to £500 with a £200 excess, whereas from memory Nationwide are something like £1500 of cover with a £75 excess) - so if you have an expensive phone that’s important.
So yes, agree all-in-all that as a single person they don’t tend to be great value, but I’ve found that in circumstances where you want more than just “average” travel insurance or you want to cover an expensive phone, they are worth considering
EDIT: Also, I should have said, there is value in the ease of it all. If you’re arranging a big trip then killing many birds with one stone is less hassle and IMHO worth a small premium (yes, first world problem, I know!)