MS isn’t punishing people for using SMB2, or SMB3 if using the latest single bay My Cloud firmware. More likely there is something wrong with the LAN configuration, or PC network settings, or with the AV/Security software on the PC that is causing the slowness one experiences when using Windows File Explorer.
If possible, one should test on a second PC to see if the problem can be replicated. If not that indicates a problem with that one specific PC.
