There is no such thing as a free game made by a studio. Full of micro transactions.
People will pay multiple times over what a one time purchase game costs.
There was a game made to actually show you how the manipulation tactics work. By someone who used to work for a studio that employed these tactics.
This video is a humorous review of the game that I recommend for those looking to be informed more on how it all works.
https://youtu.be/QtxY9J3AM_s?is=x03q105QVi3m-6PD
Otherwise the reviews on steam are also very informative.
https://store.steampowered.com/app/416760/Pay2Win_The_Tricks_Exposed/