I can definitely sympathize with this. I've been in a situation before where I was employee #1, hired an entire team of developers and built a complete product all the while being baited along with promises of "we'll discuss equity later", "we'll incorporate later" etc. Originally our understanding was I'd be a co-founder with double-digit equity (this was the main motivation for being OK with taking a salary 30% below my typical market value, even though we supposedly had "millions in the bank"). All the while this was intermixed with the most toxic micromanagement, gaslighting, and unrealistic expectations disguised as performance shaming that I've ever seen at any company ever (though strictly speaking this was not a company -- we were all self-employed because the guy was too lazy to incorporate or provide benefits). Eventually I left when none of these promises panned out and morale was at an all-time low because of the constant negativity and direction changes from the CEO.

Not saying that he wasn't... as much as a "late" co-founder is a thing... just that the motivation for making hime that might have been a little bit sinister.