Within a niche there is an easy-to-execute plan, but the returns are capped.

Niches are easier to get a toehold and then grow that into a durable (but small) position.

Niches are defensible, small enough that once a player is established it's very hard for a competitor to muscle in.

Like a little protected cave.

Niches are less vulnerable to execution risk or competition within the niche, more vulnerable to structural risk that invalidates the entire niche and its whole neighborhood.