Hell, the entire reason the internet moved from Holy Grail layouts to singular sidebar and vertically integrated layouts was because CSS can't into Holy Grail.
With how wide most users' monitors are ever since 16:9 became commonplace, Holy Grail should be the ideal content presentation layout because it uses all that free space on the sides for non-content (eg: navigation) so precious vertical real estate can be dedicated to content.
HCI dictates how humans use interfaces and with that comes many defacto reasons why a plain text page does not solve the problems users want to solve. Do you not think websites test into the optimal performing layouts and content distribution? If it worked better, we'd all be using it (it doesn't).
No, I think most website devs left to their devices optimize for least effort to create and maintain.
...which is definitely not tables. Flexbox is much easier.
I've been writing web code since 1995ish, so...
> There was never a golden era like you describe (it was a time of conflicting philosophies, people saying "eh, let's add this, that would be sweet", and browser vendors competing to add as much as possible to out "innovate" each other and the limited specs)
I did not describe a golden era of HTML, because a golden era of HTML was precluded by the introduction of JS/CSS. Had JS and CSS never been invented, we might have achieved a golden era of HTML, but we would have needed web standards to mature before that could happen. What happened was, web standards did mature, but they matured to serve websites rather than users. As a result, mature web standards center around JS and CSS, leaving HTML anemic and weak.
What we have now is a time of conflicting philosophies, with websites competing to add as much as possible to out "innovate" each other. Users still suffer the same inconsistent interfaces they did in 1997, it's just that instead of browsers being inconsistent, it's websites that are inconsistent.