Your contradicting yourself there but it does prove what you say, and I entirely agree. The core basis of SEO hasn't changed, like you what I did in 2006 still works today ie content, layout, keywords (relevant one's), correctly working site (no broken links etc), domain name (doesn't hurt to have a relevant one) and user experience. That hasn't changed, not from my experience anyway. The only moving goalpost in seo are Google adjusting their algorithms to defeat the seo "experts" who try to rank less relevant sites by dubious means. So if your "expert" is telling you seo is a ongoing monthly commitment I think it's safe to say they are not actually making your site seo friendly, rather the opposite.