So he doesn't miss any game in IPL?
In one IPL T20 Match, he bowls a tiny spell of 1 over X 4 times. And usually doesn't need to bat... Also rest perhaps when he is not bowling...
In tests he needs to bowl more than 4 overs in a spell of a match and more than 5 such spells in an innings! 10 spells in a match! (within 5 days). Besides he has to field for longer time and also at times (most times) needs to bat (take blows and exhibit some defensive skills)
One IPL match probably gives him 10 times the money of a test match!
It is physical, mental and financial exhaustion! Only thing that drives them is playing for "country" in a "premier" format!
Solution for this cut out all fast foods, junk foods, fast work, heavy machineries, automated systems, electronic gadgets, modern amusements, etc, etc. Get back to old age of being happy with sober life! Get people (mass) to find lots of free time... Probably we should also switch back to radio commentary, few camera angle coverage on Single National TV, etc....
Since this is not possible, you should be satisified with whatever that's being offered (we are lucky to see 5 test match series between top teams!) Good quality cricket, coverage, commentary, analysis... Just that we are missing some players in the form of injuries, work-load, etc.
Marshall, Ambrose, etc, were not required to deal with IPL and round the calendar cricket engagements... (T20 leagues are unfortunately paying for Tests today... Rich boards are able to remain rich... ICC makes sure they get funds from richer boards to nurture the smaller boards)
I request you to request your friendly Pakistan to first stop PSL non-sense and stick to international and proper domestic cricket! Let the sane people first start it and make it a success... Let them come up with terrific team - strong & fit & skillful bowlers (fresh & motivated to play for their country with money being secondary to them!)