Mild hybrid gives such minimal efficiency gains that I don't think it can be called a hybrid. They aren't even on the same level as something like a 'proper' hybrid Lexus or Prius in terms of electrificationBut the proper plug in hybrids you don't want a battery that's over 5-7 years old (so newer car) . So I'm told..
I think mild hybrid is the bridging gap for the moment although I don't want to get my hopes up then and it turns out it's not actually doing anything