The issue,is some of the stuff spread before the B450 launch was fear mongering about "split 4 phase designs" which was rather hilarious since such designs have been used back in the Bullozer and Phenom II days,so it doesn't mean all doom and gloom. I remember telling people years ago that an "8 phase" design being a doubled up one,which has their pros and cons.
In fact looking a the Techspot/HU analysis of the boards,it seems much has not changed but the biggest thing to look for is,VRM cooling.
A number of boards have poorly thought out VRM heatsinks and have huge plastic shrouds which causes them to get too hot.
Plus people also need to consider reference VRM designs are made for horizontal coolers as they blow air over the VRMs,so if you use a vertically aligned cooler or an AIO water cooler,you need to have good case airflow so the heat gets removed from the VRMs.
Some of the Intel CFL boards also are not up to the task,like the B360 board used in this MSI PC:
https://hexus.net/tech/reviews/syste...-a-8th/?page=3
Those VRMs are probably not getting much airflow.
Look at the Core i7 8700 being held back. Put that Core i7 8700 in a better board and it will perform better. I just feel you need to scrutinise both platforms equally,otherwise someone might think you can use an Intel CPU in a cheapo board and it will be fine,and the opposite for AMD,ie,a false sense of security.