I just signed up for ProtonPass and started to import. I have many folders but only have a main folder and subfolders for some accounts. The import failed multiple times because it could create a new "folder" as a vault but couldn't create a folder in the vault. So the import appears to not work, and it will be next to impossible to figure out what happened because the message was too generic. So now I have to go through the process of manually verifying everything. The idea of a folder structure for a product like this iis so basic it never occurred to me that it would not support it.
Compounding the problem is that the import does not tell you anything meaningful about what it is doing with my data when it fails. If you can't add folders you need to at least make the import process more transparent and informative. I can't afford to trust my important data to this product exclusively if I don't know it is even stored.
I have multiple clients and keep access to multiple business systems. I can't afford find out months later when I need ot access one of those systems that my creds were not transferred and only exist on a system I no longer have access to. Fix the import - preferably by adding the folder capability, but if you don't, I will have to stay with my old password manager just to avoid being unable to access a system at a critical time. 50 vaults is not enough and I can't keep them all organized without subfolders

It's kinda of duplicate of this suggestion: https://protonmail.uservoice.com/forums/953584-proton-pass/suggestions/46872289-tags-to-organize-entries

Tags is like folders, but better, except if you really need to put entries inside folders inside folders inside folders, etc.
And, as Maurits said, you can create multiple vaults. Currently, it's what I do:
- one vault for my personal life
- one vault by client

You can make up to 50 vaults, where you can organise your passwords based on category. Why would you want to make folders?

I am really wanting to move to Proton Pass from KeePass. But this is a deal breaker for me.

I am very much for this as well. Whether it be folders or sub-vaults. Some way to further split up entries would be nice.