The same thing should look and behave the same way everywhere, and follow platform convention where one exists.
Heuristic · Nielsen heuristics
Tag
consistency
Entries tagged consistency, drawn from across the library. Tags cut through the section structure, which is where most of the useful connections are.
4 entries across 3 sections
Type
Category
Level
4 entries
Elements that look alike are assumed to behave alike, which makes visual language a promise.
UI foundation · Gestalt principles
Repeating visual treatments builds a language users learn once and apply everywhere.
UI foundation · Visual design
Count what is actually in production before deciding what the system should contain.
Design system · Practice