No paper from me or my lab will ever be submitted to an MDPI journal - including any of their superfluous "special issues". I will very rarely (if ever) cite MDPI papers. And I will never review for them.
deevybee.blogspot.com/2024/08/gues...
The same goes for FrontiersIn journals, among others.

My experience as a reviewer for MDPI
Guest post by René Aquarius, PhD Department of Neurosurgery Radboud University Medical Center, Nijmegen, The Ne...
POV: You receive an email from a predatory journal inviting you to submit