How many roles before promotion?

I keep seeing posts here about sideways moves and my old G7 seemed intent on only applying for G6 roles despite his current role being his only experience at G7.

I had always assumed you should do at least 2, maybe 3 G7 roles before being ready to be a G6. Same goes for other roles. I am a policy generalist so maybe that’s why, but it seems others don’t agree and want to rise quickly.

Am I being a chump for wanting a wide breath of experience before moving up? I’m a G7 who’s worked in the civil service for about 7 years.