So, in his 6 peak years he got 3 cls.. not 1 in 10.
It's a decent record, no doubt, but considering he is supposed to be the very best, it could (and should have) been better. Maldini and Seedorf, for example, have 5 CLs; as does CR.
I don't think anyone here denies he could/should have won a couple more. The question is whether that is entirely his fault (of course, it isn't), his coaches (probably more), the Club's (i.e. Barto signing a thousand broken players for 100m), and other factors. I think a fair assessment would include elements from each of these factors.