Just because someone triggers your deepest fears and insecurities does not mean that there is something pathologically wrong with them.
Chances are good that you trigger theirs too.

I can't find it atm, but I recently came across an old tweet from @HeidiPriebe1 about the excessive trend of calling people "narcissists", and how many people who do this may simply be insecurely attached individuals in a relationship with someone who is dismissive avoidant.

The disnissive attitude seems "narcissistic" to the anxious partner, even though they do not have NPD.
I totally agree with this, but I also have seen a similar phenomenon happen the other way around... where a dismissive avoidant thinks their partner is crazy or narcissistic

for having emotional needs instead of focusing on things of a more practical nature that the dismissive thinks are more important.