Just wow...
Strahd is terror and refinement incarnate. He is not an armored battleship. Strahd uses cunning, intellect and charisma to get what he wants. Brute force is for the weak minded. Sometimes it is necessary to use some, that is what minions are for.
Translation: Strahd is cool until he actually tries to engage the party in combat, then he gets blown to smithereens. If this was just one poster’s experience I’d take it with a grain of salt, but there have been a plethora of testimonies here and elsewhere that Strahd is extremely fragile, and if you have the weapons he’s weak to (such as the Sun Sword) then many of those “cunning” tactics are disabled.
Strahd will target the weakest party member. He will charm, he will harass the party. He will wear them down. He will lure the heavy away from his target with illusion or lead them into deadly traps (of which the castle has a few).
Better hope team PC doesn’t make that save then, because if they do then Strahd might not have the opportunity to fade back.
The stat block of a monster is not the end of it. It is only the begining. Some monsters are as you want them, mindless brutes. Others needs skills and deviousness to be played to their full potential. Strahd is one of them. He was in the chapel but he led the party on a wild goose chase. I slew the wizard and while they were battling him, gargoyles stole the body. Then it was the cleric's turn and so on. Was it fair? Hell no! But Strahd is not fair. He plays by his rules alone. If you let such a character get into the party's trap, you play him poorly.
There is no DM that can play a character perfectly in such a way as to never have things go awry short of simply invoking DM fiat. I consider this a strength of the game, but similar to the above example, sometimes players simply resist his traps and charms. When they do so, I’d prefer the big boss of the entire campaign not fold like a house of cards, as others in this thread have attested to.
Through my play, Strahd enforced the 6 to 8 encounter per day on the little group. They died as they did not know how to manage ressources. They were young but I showed them that RPG are a thinking man's games. Not a mindless hack and slash fest. Now the young DM is putting more time in preparation and reads his MM with a lot more attention than before. He learned and his players did too.
So what you’re saying is a bunch of inexperienced and likely un-optimized players made silly tactical choices and paid for it? Shocking, that.
I’m not normally one to nitpick tone, but seriously dude, get off your high horse. D&D isn’t some master-crafted exhibition of the fine arts, it isn’t the “thinking man’s game”, and you’re not a wizened elder for capitalizing on people who don’t know better. This is a game where we crack open some drinks, eat snacks and pretend to be elves and (not)hobbits.
If you play the game as it should be. You'll find that the game is well balanced, even if you use every single options in the book. It just take a bit more preps than you might be used to.
“As it should be”, huh? I like the one-true-wayism thrown in at the last minute. To address your point though, no, there is a clear rift of what people consider balanced or not, based on any number of factors and virtually every aspect of the game has been nitpicked at some point or another on these boards, and presumably others.
More fundamentally, this isn’t even related to complaints about Strahd or 5e monsters at large, since it’s not like people are complaining that fighters in particular are putting him through the ringer, just that he getting demolished by parties in general. That has everything to do with monster design and nothing to do with whether the game is balanced or not.