My thoughts on tvp late game.. (as in maxed both sides 3-3)
The problem with super late game tvp isnt just chargelots, its that terran has no good gas dump in tvp whereas protoss has ht/archon and collosus. That and mass chrono boosted WGs reinforcing way faster than terran can, and a near non existent defenders advantage compared to TvT and TvZ for T.
All of the terran units are already super mineral heavy so hellions don't really help. If protoss is only making chargelots obviously just mmm should beat that.
Maybe terrans should actually start taking scvs off gas after 3-3 is done or something, haven't really seen this at pro level yet but I don't see why not.
Even korean pro terran float tons of gas in late game tvp because ravens will just get feedbacked and have short range, siege tanks suck in tvp, thors are slow compared to hydras off creep and bcs without upgrades suck, they will also all have terrible upgrades compared to protoss if you were going bio. Mass Medivacs become more useless as the game goes on as Protoss attack damage actually scales throughout the game via archons and collosus gaining more than +2 / +3 damage per attack upgrade when they already do splash damage.
This creates a situation where terran will often be spending all his minerals but cannot seem to trade cost effectively / keep up with protoss after engagements because protoss can spend all his gas on ht/archon and collosus which are both great high dps splash gas dumps. The counter to HT/archon and collosus are Ghosts and vikings so terran builds them but unfortunately their mineral to gas ratios are 2:1, so back to the same problem not enough mins or not enough uses for gas.
A stock pile of gas for protoss can be used to instantly warp in mass ht into archon after a major battle(if you were going mass collosus before this is pretty much the most ridiculous instant tech switch in the game considering you only need a single templar archives to do this and terran has to have been building viking to counter, which will be relatively useless vs the archons). A stock pile of gas for terran is pretty much useless. Nukes have been attempted to be used in pro games but often just simply don't do enough damage to justify the cost considering how often the ghost dies and the nuke won't even go off making it a 300 mineral 200 gas loss.
I'm not saying the MU is imbalanced as a whole but rather explaining why terran should not typically win in lategame 200/200 situations where both sides are stock piling money because it's like terran can only effectively spend one resource compared to protoss having two available to him. The way to avoid this situation is playing well during your timings when bio is still really strong and protoss is still teching up / expanding and has not built up a bank. Using stim timing/ medivac timing / upgrade timings to do as much damage as you can before protoss has 3+ base up and running . Basically making the most of the period where your gas income is actually incredibly useful.
Unfortunately this creates a situation where games are likely determined long before they are over to any keen observer who notices the terran has not done significant damage during his timings due to either making a mistake or protoss just playing well. This often leads to a slow death for the terran where the protoss just turtles and the terran finds it impossible to engage but knows he has to as every second of gas and chrono boost/WG stock piling means less chance for him to win as the chronoboosted reinforcing warp ins will be too strong. It also makes the MU very boring imo.
It also makes the MU reliant on map balance.
If the third is hard to defend and drops are easily done (shakuras) then the macro game will favor T. If the third is easy to defend and the map has long rush distance and/or is hard to drop (cloud kingdom,entombed valley)the macro game favors P..
I also don't know why people have to insist that super lategame tvp is winnable even if protoss doesn't make a huge error. It's like insisting there's a way terran can win vs a zerg in late game that he let drone to 80 drones max hive army and full larvae stock before putting any pressure on if he just plays right. The difference between pressure in TvZ and TvP is tvp pressure almost completely revolves around protoss missing a forcefield which is map based and frustrating for both sides. Hopefully the MU improves in HOTS.