We have used middle names to place our kids within their family, they are in some sense family names.

Common uses of middle names in the UK include to give a child a name of a God-parent or other significant non-family person, or to record the mother's maiden name, or to give an alternative name a child can use (if they prefer that name) later in life without having to change their name, or to disambiguate (John Frederick Smith, son of John David Smith, son of John James Smith -- they might all go by John outside of the family and be Freddy, Dai, and Jim at home, for example).

Middle names (especially unusual ones) make name collisions much less likely.

> give an alternative name a child can use (if they prefer that name) later in life without having to change their name

This is an underrated reason for a middle name.

My dad didn't have a middle name. In Canada that caused more problems than anything; forms would constantly be denied / sent back / whatever because whoever processed them would think he forgot to fully fill it out.

As someone with a middle name, it has never caused me any problem when filling out forms and the like.

I wish I could upvote you 10x. I have a middle name and it is extremely annoying that it pops up everywhere and I always have to remember to fill it out.

Even worse is that where I am from there is no legal way to get rid of it (and believe me - I tried). This means that until the end of my life I am stuck with a name that no-one uses, I personally very much dislike, I always have to enter in forms and can't get rid of.

This - please don't burden your child with a middle name or even worse, two middle names.