That’s so oversimplified that it borders on being a lie. Yes it happened, but the why of it wasn’t as simple as just “sell more lightbulbs”.
I can’t link it right now, but go on YouTube and find the channel technology connections. He does a deep dive into the history of the light bulb and the phoebus cartel. TLDR: believe it or not, it was actually a good thing.
Now there’s a conspiracy theory I can get behind. He’s financed by big toaster.