That article is a bit misleading.
Your frontend framework will not magically get "outdated" after a few years. React has been going strong for since a decade now. Moreover, even "dead" frameworks such as Ember are actively maintained.
I would suggest using Next.js on the frontend for a medium-sized app.
It always depends on what kind of project you're going to work on. My projects usually falls on the CRUD side.
For that, I keep using Django + Unpoly (check it out) + Bootstrap and I always get a SPA like app that works very fine.
And I keep my stack very lean. I'm also a backend developer so frontend stuff is just an annoyance. New language, new build pipelines, multiple deploys (frontend/backend) etc.
HMTX is also something you should take a look.