Why are companies dumping billions and billions of dollars into AI right now? The math doesn’t add up for me, unless we are trying something wreckless.

What is the end goal of the large corporations that are dumping billions into AI?

I want to know what they are trying to achieve, because I ran real world practical numbers for a method to create human level AGI, and it would only take anyone that wanted to do it about $200mil and they would have it in 36 months or less.

Do they not know a method to achieve human level AGI, and they're pouring that money in to find it? (Because the method I was assuming for isn't even new, it's an idea from an old sci-fi novel, once AI hit around the current LLM level, there was a way to brute force it into a higher level AGI in that book, that is supposed to be scientifically sound IRL.) Or do they already know such can be done for only a couple hundred million, and they are investing billions because they already know they aren't stopping at human level?