I hope I’ve understood what you exactly mean, but this is what I mean:
If you have a blogsite using a powerful platform, there will be no problem and you can make your pages or even posts landing pages. There would be no limits to this too.

On the other hand, if you have a traditional non-interactive website, it will be very helpful for several reasons to start a blog with a powerful platform under the same domain name and increase the number of pages of your site, implement long tail keyword strategy with blog posts, create new landing pages (either in form of pages or posts) and help your organic SEO rankings.

Blogging is ONE of the ways you can help your site. Using a platform like optimized WordPress, you cam make sure that your new content gets indexed very quickly and depending on the copies you write, keywords you use, internal linking structure, etc, you can even get high rankings pretty well too.

Question: if certain blogs can offer unlimited static and/ or landing page capabilities, including maybe even using one as the blogsites’ home page, and seeing as how the blogs’ content activity supports SEO… does it make sense to build a blogsite offering traditional website capabilities rather than the other way around?

It suggests the blogsite is needed to support a website, when it may not have too support anything at all. Especially when well managed blogsites [especially those based upon wordpress] offer those capabilities, not to mention evolve and improve at such a rapid pace.

Chris
Kinetic Knowledge