It definitely took me a while to get used to them! I have found that running them with a 2.5mm balanced cable helps level everything out and remove some of that shrill. They were the first pair of IEMs I ever purchased (snagged them on sale for something like $90) so they’ve become a sort of old faithful to me.
But, when I started in the audiophile game, I was very much a dark/bassy headphone guy. I had a pair of Drop x Meze 99s which I thought were the epitome of quality audio and used regularly for several months. Went for a long time without using them, tried other things, got into IEMs, tastes evolved. Put them on just the other day and have them a listen and I thought to myself ‘how in the world could I have liked these??’ Ended up giving them to my brother who loves that bassy thump for video games. All of that to say, tastes do evolve/change. I wasn’t a huge fan of the N40s at first, but now I love them for clean and detailed presentation that has some space to it too. Plus, the light weight design is great for portability or working out.