I think OP's basic premise is mistaken (Here are about 5,700 results from Google Books for "I have wanted to ask", so it's certainly not true that we never say it.
And in some contexts ("I've always wanted to ask", or "I have wanted to ask for some time now"), Present Perfect is arguably more natural than Simple Past "I wanted to ask".
As OP suspects (and as backed up by his comment re 2,120,000 GB hits for "I wanted to ask"), the Simple Past form superficially seems almost 40 times more common.
Whilst I agree Present Perfect really is less common than Simple Past in OP's "polite question" contexts, the preference is nowhere near as marked as those figures suggest, since most of the 2,120,000 instances reference past time in a "narrative" context (where only Simple Past works).
But even allowing for that, I'm sure there's still a preference. I don't disagree with Barrie's point about Past Perfect Continuous (I have been wanting to ask) often displacing Present Perfect (I have wanted to ask), but there's at least one other factor in play here...
Both Past Perfect Continuous and Present Perfect imply strong links to the present moment. But in OP's primary context, "I wanted to ask [you] [some question] is often just a fairly meaningless "deferential introduction to an interruption" (a bit like the polite throat-clearing "Ahem...").
In such situations, the speaker is deliberately trying to create "distance" between himself/his words and the "present moment" (that's why we say "I wanted to ask" rather than "I want to ask" in the first place!). Obviously it would be counter-productive to use a verb form that's specifically adapted to linking events in the past to the present moment.
The past perfect is necessary when the sequence of past events may otherwise be unclear. Compare:
She cooked dinner when I arrived.
She had cooked dinner when I arrived.
However, it is certainly not 'very necessary' to use the past perfect in OP's context. Ten years ago is ten years ago whether from the perspective of today or yesterday. There is no ambiguity of sequence.
It is somewhat different if the speaker is reporting a meeting with his girlfriend at a more remote point in time:
In 2009 I met my first girlfriend in Paris. She was as beautiful then
as she had been ten years before.
Here we do have a clear 'past in the past' so the past perfect is unproblematic. As to whether it is necessary, I see no significant objection to the past simple here too:
In 2009 I met my first girlfriend in Paris. She was as beautiful then
as she was ten years before.
[Note that replacing before with ago in the above sentence changes the meaning.]
Best Answer
"You remain the coolest person I met" suggests that you are referring to a specific occasion on which you met a few people, of whom that person was the coolest. "...I have ever met" would sound better.