Infinite chakra needs to be put into context ... Like the first and second Hokage had infinite chakra when they fought the third Hokage but still lost and the reason for that was simple .
Having an infinite amount of chakra does not mean necessarily having an ability to raise your chakra levels indefinitely as in going from a particular energy capacity to raising it infinitely but like a battery which has a set power capacity being able to recharge or maintain that set power or chakra capacity to full indefinitely (my same argument on superman as he is dependent on the suns power and since the suns output and life span including the amount of suns that exist are limited therefore his power to become stronger and stronger coincides with that limit like a rechargeable battery with a limited recharger)
SO AN EDO-TENSEI CHAKRA DOES NOT GO ABOVE ITS NATURAL LEVEL FROM WHEN THE PERSON WAS ALIVE (UNLESS CHAKRA CAPACITY WAS IMPROVED BY CASTER) BUT RATHER REGENERATES THE SAME WAY A DAMAGE BODY DOES WHICH MEANS BECOMING A ZOMBIE SIMPLY PUTS YOU INTO A CONSTANT STAGNANT STATE OF FIXED EXISTENCE SO IF YOU'RE A LEVEL 9 THEN YOU CONSTANTLY REGENERATE AND RECUPERATE BACK TO LEVEL 9 REGARDLESS OF WHAT YOUR OPPONENT DOES TO YOU OR HOW MUCH CHAKRA YOU USE UP PER JUTSU .
THE PROBLEM IS WHETHER MADARA WAS RESURRECTED AT FULL STRENGTH BECAUSE IT SEEMED AS IF HE WAS AND IMPROVED TO BOOT AND EVEN IF HE WAS NOT , DOES HE HAVE JUTSUS WHICH REQUIRE GREATER CHAKRA CAPACITY LEVELS THAN HIS EDO BODY AND IS THAT REALLY BETTER THAN HAVING THE ABILITY TO RECHARGE HIS CHAKRA AND USE KAMIKAZE MANEUVERS ?
From what I remember the first and second Hokage are only at 70% of their power in ZOMBIE form currently. while I do suspect it may be a good trade off for the second Hokage as his techniques seem to be based on talent for execution rather than power level, the first is like Gaara and Kisame in that their abilities become bigger and more powerful like a DBZ character by just using higher amounts of chakra pumped into it although you would think they can just add more and more chakra to an already executed jutsu as time goes on but whatever .