Lakhs of candidates apply for the Civil Services Examination in a typical year, for roughly a thousand posts. Prelims marks don't even count in the final rank.
Walk down basically any lane in Karol Bagh and count the UPSC banners. You'll lose count somewhere around the fifth building. I've had students bring me printouts from six different institutes, all claiming roughly the same
Every UPSC cycle, geography pulls one of the bigger optional crowds. Not luck. Static syllabus, diagrams that earn partial credit, decent overlap with GS.
Every UPSC aspirant reaches a point where reading notes stops feeling like enough. Somewhere around the fourth or fifth revision, the syllabus starts to blur into one long list of facts that never quite connect during actual exam pressure.