Mistwell
Crusty Old Meatwad
Me and XunValdorl don't agree on a lot, and I think he over stated it a bit, but he is right in general here. Let me give some examples...
In a 3e game that no one track encumbrance Str looses a lot of meaning, and you may not realize how that trickles down the balance chain. The wizard puts an 8 in str because it is useless to him, but then carries 3 spell books full of spells, a magic staff, 5 potions, a dozen scrolls and 3-5 wands most of the time, plus treasure and extra cloths and components... you don't realize how much that all adds up.
Are you seriously arguing that 3e games fall apart because the wizard doesn't track encumbrance? At the levels you're talking, they can afford the lackey follower easily, if you really care. I've never heard anyone honestly argue this is an issue. I think thousands of people are playing 3e just fine while ignoring encumbrance. It's sort of proof of the opposite of his point - games don't fall apart when you remove a rule like that.
In a 2e game where you change initiative and just say roll d20, add dex mod highest first... sounds like you just made it easier, but in reality you stop a lot of spell interrupts, change the balance on a lot of weapons...
Yes, it has an impact. DOES THE GAME FALL APART if you do this? No, not at all. That was his claim. His claim is not "things change if you make changes".
In 4e if I play low magic, and at level 12 only dropped a +1 weapon, a +1 armor, and a +1 wand to my 5 players, they are going to be at a disadvantage, but it is more then just numbers you don't realize how the lack of options for daily and encounter powers on items hurt...
I agree in 4e this changes a basic assumption of the game. But, I also think the game doesn't fall apart if you do that, since you (should) know to alter challenges to account for it.
Bottom line, name a rule in 5e that, if altered, makes the game "fall apart". I think it's more than a simple exaggeration.