Grafting Tomatoes

So, I watched a short video on YouTube the other day, it was only a short one but it looked and sounded very interesting. The poster basically took two young plants, chopped the top growth of one plant and then grafted the other plant onto that root stock.
Apparently it leads to a much bigger plant with a much bigger yield, im giving it a go with a couple of varieties but has anyone here tried this method at all?

 https://youtube.com/shorts/-O-LoMzw45A?si=tZU1NmUwY-sJV57X

edit to fix youtube link