Pay of Mortgage Early VS Investing the Extra Money

30 year mortgage of about $425k at 2.9% interest. Wondering what makes more sense between paying the mortgage off early within 15 years OR using that extra money we would be putting towards the mortgage to invest into our brokerage account. We recently just started the brokerage about 6 months ago and currently have $10k in VTI/VXUS 70/30 split. ChatGPT is saying due to the low interest rate on the mortgage it makes more sense to invest the extra money. But obviously want to get some other opinions as well!