I get the impression that your solution:

  - is adjacent to using static site generators with a custom template
  - is right "below" (in the abstraction tree) a headless CMS approach, where you manage multiple landing pages from a central place

Currently the way you're positioning this, the distance to either approaches is too close for me to clearly see an advantage. However, it only comes down to personal preferences.

Or to put in a different perspective - the advantage of this being simple "loses out" to potential advantages of other approaches and might need something more to stand out.