For a single user, they're equivalent in almost every way to just having 5 or 6 folders in one vault, so the "separate vault" distinction is pretty much gone.
Basically, what I want is two separate, independent bank vaults. Opening one should not, in any way, help you open the other. I want to keep my spending money in the main vault, and my stack of gold bars in the other vault that I only open in case of an emergency. That way, the risk of anyone seeing the combination over my shoulder or sneaking in when I've got the vaults open is minimized.
What 1Password gives you is the ability to easily create other vaults, but every time you build a new vault, they put the combination for that vault on a sticky note inside your first vault and give you no way to remove it. The security of your second, third, fourth, etc vaults is irrevocably linked to that of your first vault. All your gold bars are, no matter what you do, forced to always be exactly as secure as your spending money because as soon as someone gets into your spending money they just need to look at your sticky notes and they've got access to everything else.
There's no real security purpose for having a second vault in this system. The only purpose is to more selectively control access to what other people can access (i.e., vault sharing / team features). If you want to make some of your spending money available to your wife but not all of it and not your gold bars, you can build _another_ vault, put some cash in it (and the sticky note in your first vault so you remember how to get in!) and then also give her a sticky note she can stick in her vault with the same combination. Now you can both easily access the shared vault, but she can't access your main vault or your gold bars and you have no way to know what she has in her vault at all.
Things like this and the enforced cloud sync are decisions that weren't in any way a trade-off (the path they chose does not preclude the more secure path). The fact that they keep removing the more secure option regardless really seems like a security company that's more focused on market and revenue growth than security now.