Are criminals getting smarter or police getting worse?

In recent years its becoming noticable that police have rules as to what warrants police time and effort. So if a thief steals something but it doesn't cost much i.e. less than £1000, the amount where police will make effort to try and catch them. Theives are now ensuring they steal less than that each time as they know police wont put the effort in to catch them.

This is also leading to less criminals being caught i.e. for some crimes police catch the criminal less than 1% of the time.

Similar things are happening in different crimes also, another example is where criminals are attacking people to threaten them, police will do nothing as the criminal only smashed a couple of windows or damaged parts of a car for example. The victim is left successfully threatened and has to pay for the damage. Whilst the criminal didn't even get investigated even though the police know who did it. The police simply came to the scene and made a report and apologised for this happening to the victim, then did very little about it.

Have the police become so bad that criminals are using the police (making false allegations as smokescreens to distract them) commiting other crimes?

Who do we blame for this, police lack of effort or the criminals for realising the police limitations?