R D S wrote

I feel as if modern keys promote failure to ensure the successful locking
of a door on *every* occasion.

The best of the electronic locks dont.

I'm super vigilant of late but some years ago I was surprised how many
times I was getting home to discover the front door wasn't actually
locked.

Never happens to me.

I can only presume it was down to that extra turn they need,

Mine dont.

which if you don't and further don't try the handle, fail.

Just had a new door on at work, it's a Yale lock, a stupid flat key that
you can't distinguish which way around it is to ensure you get in the
right way first time and it only comes out horizontal, which after you
give it a good old turn, needs turning back on itself to get the frigging
key out.

You should have got a decent electronic lock instead.