Has it become customary for hotels not to cancel the pre-authorisations that hotels obtain after making a payment now?

Non-cancellation seems to be worse when paying on a card other than the one presented upon check-in, but I often have literally thousands of Euro on my accounts in pre-authorisation that hasn't been cancelled (so they become 'blocked amount'), and frequently they sit there for 30 days before they disappear.

When I ask the hotel to cancel the pre-authorisation after payment, most of the tell me that they would cancel out automatically in 4-5 days but they never do - they almost always take 30 days. They almost never do anything about it if I ask them to manually cancel them.

It's becoming quite annoying, although I do not need to access those blocked amount, because it sometimes gives me a fight by reducing the available balance without my expecting it.

Is this a widespread problem, or are the hotels that I have recently stayed at being a bit incompetent?