I think the boiling is closer to 18 hours. I do a pretty good one in about 5 in my instant pot, though.

Another big problem with getting a "ramen" in a random western restaurant is noodles. If they don't make them themselves, the dry shelf stable stuff is just not good (at least what I can find in my EU country). As I was slowly upping my ramen game at home, the single biggest difference in quality was when I started making my own noodles.

I suppose if a shop markets itself as a ramen shop, you have a chance of getting a decent bowl. Most of the "asian" or even "japanese" restaurants in my city are places where they add cream to tonkotsu to make it white...