Nope you dun have to get ac serviced every season this is bs.
The problem is the newer acs got very narrow fins at the eveporator end so they get clogged very easily.
Service should be done after every 2 years time.
I always service my acs by my self, with window it was easy I have been servicing my general and national acs for years but now bcoz we sold them and got splits i only clean my evaporator every 2 months with a brush and water.
There are Metro installers here i asked them what they do in service they told me in 500 Rs they will clean evaporator and condensor and if you want us to do complete service than we have to unmount condensor and eveporator that will cost around 1500.
LG Ac needs service after 2 years hmm my kenwood chinese is running its 2nd season no prob at all. Office waves acs running without service or even filter cleaning for 5 years 