Theres probably no reason at all, it’s just a coincidence.
I interpret you reply this way.
"no reason" means it is random chaotic chance that muon-electrons exist at all and that there is no cause and effect mechansim for the mass of electron to repeat at approximately 207 times itself as the muon electron.
"no reason" could also mean that humans offer reasons and purpose but fermionic particles do not have any 'reasoning' abilities ergo humans are in error to think there exists any reason for a cause and effect mechanism of muons existence at 207 the mass of the electron.
"no reason" may also mean that there exists a reasonable explanation for why the mass repeats at 207 times itself but you dont know the exact reasons for those mechanisms of cause and effect to occur.
"no reason" means
why not why not 0.627, 482?
That is just and inversion of the question I asked you. Why is it approximately 207? Do you know the mechanism for the mass to appear and not 0.627?
If it was random chance then muon-electrons and electrons and tau-electrons would many differrent values at differrent times that we observe them. Ergo the lack of random chance means there is consistent mechanism of order that always repeats itself.
5 is a value and we can arrive at in various ways ergo there exist various possible mechanisms { pathways } arrive at the resultant value 5.
Perhaps there exist various pathways to for 0.511 to repeat at 207. Can tell me what any of those pathways { mechanism } are?