[birken]

At the early stage of a company, equity is very important to keep people's incentives aligned to work really hard in the best interest of the growing the company. This generally initially expresses itself in the founders, who have a lot of equity and little or no salary, and then continues on with early employees. So just from this perspective, spending a ton of equity on somebody who isn't contributing is a massive opportunity cost.

Additionally, there is a reason successful solo founders are rare. It is hard to found a company, especially without somebody who is 100% aligned with you (at least economically) the whole journey. I'd imagine that a situation where you start with 2 founders and go down to 1* makes it even harder, because you are like a single founder but with all of this stress you are accumulating right now on things that aren't related to making a great product.

Now this isn't to say that founder strife is something that doesn't happen in successful companies. It does. It is just the magnitude and early-ness of your strife seems pretty large. Making a successful company is really really hard, and you really want to put yourself in the best position to succeed. If you aren't in a good situation, and getting to a good situation doesn't seem likely, then just leaving and starting something else might be your best available option.

Note: I have no idea how large your company is, so this post is assuming your company is 2 or 3 people and is very early stage. If your company is doing really well or is much larger, this advice basically doesn't apply at all, because then "sticking with it" starts to look like a good option.

*: I'm extrapolating that you had 2 founders based on your post. If for instance you had 4 founders and were going down to 3 I don't think it would be as big a deal.