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.