Take a ride with really experienced folks, it will be a humbling experience.
Oh yeah I believe it's the amount of mileage that counts. You can't practice everything without putting mileage
And yet there are loads of mediocre riders who have been at it for years, decades (twenty years of doing the same thing). So while I can't imagine for a second that moving to a SS in year two is wise, hua96's training and diligence will get him there eventually. The reddit articles he links are by two riders who 'upgraded': one had five years' experience and the other 32000kms. So hua96--hang on a bit. The CBR500R is probably a good bet. I am on the CB500X in my third year and for my riding 500cc is fine. The next bike is not an upgrade but an addition: CFR250L, DRZ400S, TW250R...you see where I want to go. Not faster, just much more difficult. For speed next year I will try Racer5, on their bikes, on the track. So, er, 125cc.