There's a new CRO tool being released every every day of the week, but only a handful that we would ever recommend. Google Analytics is an absolute must for every website. Microsoft Clarity is relatively new on the scene but a perfect free upgrade for anyone still using Hotjar.
For businesses that want to run their own A/B tests, we lean towards convert.com. If you're running Shopify, then Shoplift is a great little app for data driven insights.