Yeah, they were. Though arguably not in the link you posted - those are mostly clichés, as correctly pointed out by the original poster. Especially the "separation of content from layout" and CSS Zen Garden were obviously[0] nonsense, and you can observe how SPAs of today go against both.

Tables had performance problems when they got large and content got potentially dynamic. That I learned only many, many years later - I never did sites big enough to run into such problems then.

The accepted answer in this post is cringeworthy. So much rationalization these days, makes you wonder what we're rationalizing today.

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[0] - I admit I bought the CSS Zen Garden for a while; it took me some time and experience to realize that, really, no one does that in practice, and it requires ridiculous amounts of either forethought or afterhacks to do it.