Is RankMath SEO better than Yoast?
As you can see from the comparison, both plugins are very good with their features. But there is no doubt that Rank Math is providing you more while being free to all plugin. Some useful features in Rank Math are not available on Yoast. Some of them are available in the Yoast premium version.
RankMath is completely free as of now. Whereas Yoast SEO is freemium, meaning you have to pay to get access to some of its features. Rank Math may go in the premium version after a while but as of now, you can enjoy full fledge features for free.