Because doing all your strength training in 3 back to back days, even working different groups, isnt a good idea. just because you’re not targeting the same muscle doesn’t mean it isn’t engaged as a secondary/synergistic muscle or stabilizer, therefore you’re likely not training at max capacity that second or third day due to fatigue. Also, if you’re only going to do 3 days, getting the hormone/synthesis stimulation over the course of multiple days vs having a 3-4 day stretch without it, will yield better results.
And look, sorry to keep it all the way real, but this and your other thread show that you have a problem with consistency and staying committed, haphazard workout scheduling is part of that problem and will not get you closer to your goals. Make a schedule and stick to it or stop asking the same questions/doing the same innefective training and looking for a different result. It is what it is when it comes to diet and exercise breh.
You’ve gotten feedback from multiple of us on # of days and scheduling, and absolutely none of us have agreed with your approach today, that should tell you something when mad folks on the coli all agree