There isn't any solution that directly deals in this space which makes the content creation process very distributed and time-consuming. In that respect, Google Doc will be considered as a competitor.
https://martechtoday.com/downloads/marketing_technology_land... (38MB)
If you study that graphic more you'll find a lot of solutions pitching the idea of 'no IT help required'. Trust me, that's huge relief for marketers. Another indication of a crowded space is demand. Demand for convenience.
Differentiation becomes really challenging in such a crowded space, I agree. From a product perspective, consistency in expanding the capabilities of your product can help set a long term relationship with the market. From the marketing perspective, positioning of the product should evolve in a manner that agrees with what's trending in the market.
Less effort? Is it cheaper? A quirk to capitalize while it exists?
Can you name a few companies that might be considered competitors?