MFP is free, so is LoseIt, however things begin to diverge from there. The Garmin connectivity was my major reason to move to MFP, it was already there and not available on LoseIt. Now, LoseIt supports Garmin connectivity on their paid platform and when I combine the functionality and stability benefits of LoseIt, it was an easy move.
MFP has struggled to remain stable from a technology perspective, often times the system was unavailable or some features were not working properly. I work in tech, I get it, I can put up with a lot of interruptions, but after extended periods and a continued downward trend, other options become attractive.
Since I left LoseIt a few years ago, they have continued to improve the platform. This app/system actually feels like a health management assistant where MFP is sort of like a “spreadsheet” to store your data. I suggest you try them out and the focused purpose of the apps will become clear to you as well.