I think this is a newish (as in last century!) thing whereby names are tending to become more unusual, more individual, & so it feels a bit more like someone's weeing on your turf if they go with the same name as you.
This probably wasn't a thing when people tended to choose from the same narrow pool of names - people just adopted nicknames or added descriptors eg. 'Big John' or Lizzie, not to be confused with her cousins who were also called Elizabeth after theur grandmother but answered to Beth, Eliza, Lisa & Betty.
My ds has William as a middle name, mostly as a safety net name in case he hated his unusual first name (luckily he doesn't).
Both my & xh's families are positively hooching with Williams, Wills, Bills & Billys. We all seem to have had the same grandparents in mind (xh & I both had a grandfather called William, probably because it was incredibly trendy in the first few years of the C20th).
No one stresses about this. But if two of my second cousins both call their babies by the same, non traditional name, it's handbags at dawn.
Names just go in fashions. No point getting annoyed about it.