Let's compare to Facebook, which I assume, is any social platform's main competitor.

Facebook is a strong social media competitor. I remember back in the day I thought sites like Twitter were completely redundant, pointless, and would never become popular. Competing with the big boys requires a lot of functional diversification and targeting new untapped communities.

Functional Diversification

Fortunately, Steem is not a social media site. It's just a blockchain that you can write plain text on. That text could be code, blogs, messages, or any other organization of characters.

Steemit created Steem, and Steemit is technically social media, so it gets confusing.

The main problem I've sound so far is the pure lack of commentary on this site, even amongst the most popular posts.

Is that a problem? Eh, I don't know. I feel like the Steemit site would still provide a very large majority of value even if comments were completely disabled. Most of the content that I find to have value comes from the original post, as most of the commenters often don't know much about the given topic, and often don't provide much (if any) extra value.

An interesting thing to note here is that Steemt Incorporated actually can't disable comments, because people would just go to another frontend like Busy, Steempeak, SteemLeo, Palnet, etc. All of these frontends are centralized hubs that can organize the data on the blockchain any way they see fit. Anyone in the world can create one of these centralized hubs.

The crux of Steem is the cryptocurrency aspect. Facebook would never be able to allow users to control the inflation of an underlying native currency. That would be a regulation nightmare, assuming they would even want to do it... which they don't because Libra already proves this idea. They want to retain as much control as humanly possible.

It's a lot harder to make activities on Steem illegal because there are less centralized points of attack and it exists in a borderless environment. We can implement peer-to-peer gambling here. No regulator in the world has the resources to go after random people gambling against each other. It's the same reason why torrents were impossible to stop, except crypto is far more resistant than torrents are.

Steem can create a host of services, all with built-in governance structures, that are highly resistant to censorship. The social media aspect of the platform might account for 90% of the activity that goes on today, but nobody can regulate what happens here. We have no idea what kind of functionality is going to take root here in the future.

TLDR

You can't really legitimately compare Facebook to Steem in any way.