useMemo vs React.Memo when it comes to JSX

I was on the project with some really cool developers(ex Amazon) and I saw them using useMemo inside of the jsx, like this:

So my question would be, do you think this is good practice or would you rather use React.memo for these kind of things....

• Fix the slow render before you fix the re-render

useMemo vs React.Memo when it comes to JSX