Not a problem in itself, but it becomes one when it's being aggravated by other lazy design choices (long combos, tracking, animation cancelling, underhanded input reading, exagerated hitboxes and range, etc.)
After applying these factors, the delayed attacks are nothing more than an irritating stupid gotcha
Still they could be relatively tolerable, if From used them sparsely
The problem here is the disparity between the speed and agility of PC and the enemy bosses
The PC is still figthing by the DeS principles of being "grounded" and "methodical", somewhat (BB changed that dynamic of course)
Meanwhile the late game bosses might as well have came out of Ninja Gaiden 2, as even in their basic combos they are spazzing out almost as hard as Ryu during an UT
"tracking" (whatever that means)
It means that before you deem From's fighting game design to be excellent, you should at least familirize yourself with the basic concepts of fighting game design
Essentially it's the degree to which a character can automatically "adjust" himself and "guide" an attack towards a moving target
It's a property that should be applied to select attacks with restrain, which From doesn't seem to possess
Really when you figure all these elements together, along the others I mentioned in the parentheses of my first line, what you have are the hallmarks of those quarter munching arcade final bosses
Sure, they were hard as nails, but they were also complete bullshit devoid any elegant mechanical design
Which is ironic, given that the design quality of the storytelling aspects weaved into these boss battles are the strongest they've ever beem - From has mastered that "fable"/narrative side, but degenerated into the worst qualities of the game side
My guess is that 90% people instead of learning how to play the game ended up brute forcing their way through bosses using cheese. You can't do this in the DLC because stats have been maxed. Elden Ring was a bit like this too towards the end.
And that is also a BIG problem
Perhaps even more so than the previous issues
I mean, like it's DS predecessors, ER is sold as an RPG
It has a fairly robust character building system, hundreds of equipment pieces and dozens of magical abilities, all pooling up to millions of possible character builds
Plus there is no official text, both in-game and out-game (From's own marketing), that discourage experimentation and diversity of playstyles (in fact it always the other way around)
All of this creates the expectation that these options, at least the majority of them, are viable enough to allow the player to reach the credits screen
So, for most of the campgain the player can go about the various challenges however he choses
Everything in the mechanics support that and the sandbox open-world format further reinforces it - "Getting your ass kicked? No worries, go do something else, clear some trash dungeons, farm a bit, explore that other area. Then come back after 30 levels, give or take, and rofl stomp everything in your path."
But then, by the very final strecth of the campgain - and now the greater part of the DLC - the game turns around and says "Liking your current build? Well fuck you, you were actually meant to play like X the whole time."
Either way you look at it, this is a serious problem