I enjoyed your article very much but I think you are assuming people only use 1 thing (for example Angular/React) and that is it .
Just like with old server side rendering where you use multiple technologies to accomplish your goal I think the same is true in this new paradigm.
In a “new” full stack I think you will not only use Angular/React but also some kind of static site generator which will render everything but your dynamic parts. You will use some node/express app for your main services and you will use some kind of APIs for anything else (like search).
The great advantage I see here is that the majority amount of work done on your servers is off-loaded to the client (which is only possible since the advancements that have happened the last few years). Every time you are doing a search against your database your server is in the middle doing work. Anytime your page updates the your server is in the middle rendering that HTML.
It’s beautiful to have lots and lots of users but only 2–3 servers because all the work is done on their CPU/Network compared to your monolithic app.
I guess the main thing I want to say is that you should use both for their correct use-cases and to get the most out of your system.