From my own experience I would say so. Technically platforms like Instapage, which I have extensively used, do have an SEO feature built into them, although I really don't think they work - is very basic and any good SEO person would know that meta tags and key words are only the tip of the search iceburg.
Landing pages should always be a/b optimized, if you can pull that off yourself without these platforms then go ahead because ultimately you can customize to full seo needs.