Your assertion that older frameworks 'became a mess at scale' is a sweeping generalization. Any technology can become a mess if not properly managed; that's not a failing of the technology but of the architecture and development practices. PHP, for instance, powers Wikipedia, one of the top-ten most visited websites in the world, and it handles this scale quite well.
The emergence of frontend frameworks was not solely because 'existing solutions did not scale'; it was also driven by the industry's evolving needs for richer user experiences and faster development cycles. These frameworks solve specific problems but come with their own trade-offs, including complexity and steep learning curves. To dismiss alternative approaches as unscalable without evidence is not just intellectually lazy; it's a disservice to the field of software engineering, which thrives on diverse solutions to complex problems.