Go on a job board, search for React/Vue/Your-Favorite-SPA-framework, go to their website and then see if there are any features that would actually justify an SPA.
Some examples: the Airbnb website, the New Reddit, etc.
They have a full wysgi for theming built in, a real time chat app, a video sharing app, multiple messaging platforms, and methods of bundling multiple subreddits together.
They added all this really fast, due to the nature of the platform being an SPA.
I have the same issue at work. Any given feature in isolation could be done simply as a jQuery plugin, but together the only way to make it seamless is an SPA.
They have a good design staff, but there was so many minor decisions made over the years that no knew exactly what was a necessary feature of the UI and what was just fluff.
They needed some real world testing to get a better design.
I strongly disagree; most of the projects that I worked on a decade ago that lasted more than a few months ended up with ad-hoc frameworks or conventions implemented in vanilla JS or jQuery that varied wildly in quality and changed frequently through the lifespan of the project. In my experience React/Vue/Angular with their generally well engineered and thought-out principles have resulted in a huge boon for productivity for long term projects in a team environment.
> Most projects do not have any requirements like real-time UIs
Whose "most projects" are we talking about here? Yours?