Probably yes? We do have some algorithms, "sort by hot", "sort by active", etc, so there is value to getting to the top of those lists.

No, the algorithms are always there - otherwise, there is no "feed". It's just that the algorithms here have no hidden weights to drive engagement towards specific topics/posts. Not that it can't still be manipulated, but that's often detectable behind the scenes, too.

I think so personally, because it's still engagement and I'm assuming it probably contributes to the MAU number which could in turn attract more users

Any intentional choice made to capture human attention functions as an algorithm.

For instance, when a creator posts an intentionally silly title, it triggers a predictable urge in users to comment on that silliness. This deliberate cause-and-effect cycle means the creator's strategy itself is the engagement-driving algorithm. A good example of this human-designed system is ragebaiting which systematically uses manufactured outrage to multiply views and comments