I can´t recommend to use a protective filter.
It is indeed more or less the same as having transparent plastic on your sofa for protection. One could also think about condoms as another example. The additional protection ruins things, but some people would be in pain had they not used protection.
I used filters earlier, but noticed that without them outcomes were better. I still have the filters just in case I need them for something.... Haven't needed them yet and my front elements are doing just fine.
1) an expensive lens + a cheap filter = crap
2) a cheap lens + a cheap filter = crap
3) an expensive lens + an expensive filter = worse than the plain lens = crapUse the lens hood.
In most cases hoods are useless for their initial purpose, but they protect front elements nicely.