Agree, and the ordering matters: rendering mode is somewhere near the bottom of the list of things that decide whether a page ranks.
Above it: whether anyone searches for what the page is about, whether the page answers it better than what already ranks, whether the site has any reason to be trusted, and internal linking. I have watched teams spend a quarter on rendering while every page sat three clicks deep with no links pointing at it.
If you move to server rendering, do it for the user-facing speed and the previews. Both are real. Just do not expect the ranking to move on its own.