I also found this to be the case, I think the ELO system they implemented when I was playing in the WoL era to be quite accurate, I was quickly able to rise through bronze but found people that were more or less equally matched to me at high silver and low gold. Was enjoyable and not huge fluctuations in skill level except for the occasional unavoidable smurfer.

I did find that 1v1 was definitely more balanced than team play, so I think both you and parent are correct. In team play with friends we were much more likely to encounter people of radically different skill levels playing together.