I agree with you on this one. You might not know this, but the
massive pay rises only affects the senior officers [ie inspector,
asp and above], scholars and their ilk. The typical frontliners get
much, much lesser. A pittance of 'few tens of dollars', as put by
one forumite in another thread.
For example, in the past many municipal duties like security
patrolling were carried out everywhere by the police. Now police is
excused from patrolling private estates who is expected to employ
their own security guards and when there is a crime the security
firms could lose their licence.
That's where you're very, very wrong. They do conduct patrols at
private estates, regardless of whether there are security personnel
employed or otherwise.
Similarly all the fire safety duties and alterations and additions
and electrical and work site safety controls were passed to the
citizens and even checking on and application for public
entertainment licensing within private housing estates have been
transferred to the various management corporations whose staff
could be fined for failing to perform certain duties.
Shouldn't civil defence come into the picture for fire safety
matters? Anyway, application for public entertainment licenses is
gone through police for people living in hdb estates. For private
estates... The management of the said estates would act like what
town council is doing for hdb estates. So naturally things which
involve permits like entertainment licences, permits for
renovations will go through the estate management anyway.
Immigration check to prevent entries of illegal immigrants were
passed on to private landlords who may be fined or jailed for
renting out flats to illegal immigrants when traditionally
policemen were responsible to check on them through the check
points and other hideouts.
There is a reason why ICA is set up, to specialise in such
matters. However, having said that, you will be surprised to know
that the Police are the ones doing the bulk of these Immigration
Act-related offences.
Mosquito breeding caused by lack of proper treatments of public
drains were not passed to the flat owners as officers' failures to
perform checks were spared whereas flat owners could be heavily
fined.
This one is under jurisdiction of NEA. However, if need be,
Police can also take charge of the situation. However, the only
thing they can do is to obtain the particulars of the offender, and
the details of the offence. After that, they can only forward the
information to NEA, who will then conduct their own investigations
and process the punishment meted out.
Housing board has transferred their responsibilities for defective
construction to flat purchasers who could be fined or jailed for
any incidents of window dropping.
Police involvement could be because of the circumstances of the
case indicate that there is enough grounds to charge the person for
an ofence of rash act, or negligence which allowed this to happen.
And... what does this have to do with the Police again? 
Just imagine by doing less and lesser all our policemen and
ministers are still claiming to be worth more and more and many of
them are asking to be paid higher than the S$300,000.00 pa for
sitting around and trying to cater to passers-by enquiries which
they call successful policing which deserves more pay
rise.
You're wrong about doing lesser and lesser. The thing is, they
still do the same things. It's just that nowadays, instead of just
the Police, other agencies also have powers to take enforcement
actions for certain matters.
So the Police do the same amount of things, possibly more nowadays,
but there are certain matters which can now be enforced by other
relevant government bodies.
The Police's job is to enforce all sorts of laws under the sun. But
whether they are the lone agency to enforce it or have other
agencies to help enforce it is another matter altogether. 
