Oh course he has investors. While he is the majority stake holder he didn't buy Twitter with his pocket change. He has loans from several banks and a hand full of Saudis at a minimum. All of which likely have SUBSTANTIAL interest rates given that it's a loan for acquisition of a loss leading company

(Source from Routers with some incomplete numbers: https://www.reuters.com/markets/us/who-is-financing-elon-musks-44-billion-deal-buy-twitter-2022-10-07/ )

He offered severance yes but that's not the point and irrelevant to this conversation

him using his own persona accounts to finance his shit show at this point that's on him and because he fucked up by coming in way too hot and torching any good will he might have had from outside investment. You can track how he typically finances day to day operations by looking at any of his other companies. They are all run similarly at the macro level.

Plenty of tech companies run at a loss and grow for substantial periods of time. It's not in and of itself a cancerous place to be as a company when your product will take time to get to a place where it is marketable. Those companies often being an IP to a functional state and then sell it or are absorbed into other much larger companies like Google/Facebook/Amazon. So much so that it's become a trope on TV with shows like Silicon Valley.