He had 26 matches all year and was more banged up than ever. In 2018, he had 140 matches. It's not the amount of matches, or even the intensity, it's what he's doing outside of the ring.
I can absolutely appreciate and respect that MJF put on a lot of muscle during his time off, and I don't think it was all or even mostly "peptides"/illegal substances - he's clearly been working his ass off. But I do wonder if he's doing too many low-rep sets of multi-joint exercises (Squat, Bench, Deadlift, Weighted Pullups) and putting too much stress on his joints, tendons and ligaments - and then trying to wrestle indy/lucha style matches that are causing over-use injuries. Putting on that much muscle in a short span (a year) doesn't give your joints/bones/etc much time to catch up, especially when you're adding hours and hours of conditioning on top of all that lifting.
Now that he's built the muscle, it takes much less effort to maintain it. So, upon return, MJF is going to have to make a choice -- low-rep powerbuilding, LISS cardio, and wrestle a safer style...or switch to high-rep bodybuilding, dynamic conditioning/plyometrics, and he can do all the flips and springboards and topes he wants. Yes, Macho and others could get away with it - but that's because they were legitimately injecting hormones and built up their bodies over a decade plus, not less-effective pills/peptides over a 1-2 year period while barely wrestling.
Here's hoping MJF will come back stronger than ever. He really needs to take a closer look at who is in his inner circle, no pun intended, because they're pulling him in too many different directions.