No one will argue that opaque identifiers is a sufficient security control but it's (slightly) better than nothing, at least it would've stopped a naive enumera

No one will argue that opaque identifiers is a sufficient security control but it's (slightly) better than nothing, at least it would've stopped a naive enumeration approach to scrape everything. Don't get distracted by that part, the main reason is many companies wouldn't want to publicly post a dashboard of how many users/entities/widgets they have for all to see but exposing sequential identifiers basically does that.