Would you care to share some 'bugs'? I'm always pretty interested in those things, despite never having had a.. session(?) myself. I know of one where you used a Spiked Chain, made yourself a giant(?) so you got a big boost in combat stats, and because of how the chain works you'd almost always succeed in tripping someone, and when they got up got a free counter attack that again could trip them. Another one I do not know the method of (except that it has to do with Simulacra and Wish) which let's you basically make infinite copies of yourself.
In our Pathfinder campaign, we have a level 10 evocation (fireball, pew pew) halfing (I think?) wizard with a raven familiar. Said wizard has permanent Reduce person (so to be a tiny creature) and their familiar has permanent Enlarge Person to make it a small creature. The wizard sits in a backpack on the crow, and for roleplaying purposes (wizard lost a bet to familiar) the raven does all the talking and casting.
Before feats, the raven can fly 40' a round. Between that and items to allow for empowered and maximized fireball and scorching ray (I think?), our wizard regularly drops between 60 and 120 damage per round.
I suspect GP is referring more to complexities in the gameplay, not loopholes (though I'm sure 5e has fewer of those, by nature of being less rules-heavy and more reliant on the GM's interpretation). For example, weird corner cases like grappling rules have been greatly simplified. So have skills, weapon selection, and combat rules in general.
As late as 3.5e and Pathfinder, you could easily spend 5 minutes figuring out how to resolve a single 6-second action according to the rules. Say I'm grappling someone (complex rules) and move them across rough terrain (5-foot step or not?) while threatened by an enemy combatant (attacks of opportunity) with while under a Bard buff (pluses to defense)… figuring out who attacks whom when and how can easily involve flipping to many different sections of the rule book. Whereas in 5e half those rules don't exist and the remainder are simplified.
My understanding (not from experience) is that previous editions had even more complex rules than 3.5e, and 4e simplified the rules in the "wrong direction" (away from role-playing).
In first edition the Armor Class went from 10 downwards eg AC -2 was awesome. And you had to look up tables (before 2nd edition added the slightly simpler THAC0). That was changed such that numbers always go up and similarly, higher dice rolls are always better (in some circumstances in 1e you wanted lower numbers).
The concept of advantage or disadvantage. Sometimes you'd have to do a bunch of calculations eg -4 for being invisible, +2 for this, -1 for that, etc. Now, you just figure out whether someone has an advantage or disadvantage. If neither, it's a normal dice roll. If advantage, roll 2 dice and take the highest number. If disadvantage, roll 2 dice and take the lower.
Some classes were crazy powerful, and others weren’t. It was easy to get into a situation where one player would dominate the game. And not really on purpose. Now the classes are much more even. Everyone gets a chance to shine.
