Investor money.

The real answer is that there is currently an AI arms race (mostly) between Google and OpenAI.

The way that the modern internet economy works is that the winners generally take the majority of the market and everyone else takes the scraps.

I work in machine learning and have spoken with some of the Google engineers about it recently. They said that when ChatGPT blew up last year, it sent shockwaves through the whole company. They had thought that they were ahead on AI, but suddenly realised that they were WAY behind.

Now they are putting a ton of effort into trying to push new models and uses because they are worried about becoming the "Bing of AI" rather than the "Google of AI"