Horizontal Sharding in Prometheus

Example : Prometheus servers = 2, Nodes/Targets = 4

Use of Horizontal sharding described in video, To split targets among various Prometheus servers. It can be 50-50% or 25-75% etc.
I can say this is kind of automatic horizontal sharding where nodes are getting spitted automatically.

(Without Horizontal sharding) If I manually divide them among independent servers like P1-2, P2-2 (50-50%). I can say this is kind of manual horizontal sharding.

Video link - https://learn.kodekloud.com/user/courses/prometheus-certified-associate-pca/module/def44ace-3439-4128-88c2-b701bf182baf/lesson/74055a28-cbf5-4021-bd6d-73fcac46c1f6

In which case horizontal sharding is useful ? Because if this is “Horizontal sharding” then I will go with manual method.