Problem with any paint finish is eventually deteriation due to UV, sometimes called oxidation or weathering.
Extent of problem depends, among other things, on the quality of the paint, the degree of exposure and any protection you may apply.
At one time I worked for a company which made ACPs , used to clad Building facades, and we were able to make "self cleaning" panels and give a twenty year warranty against weathering. Non inflammable ones!
But the paint cost was $20-- per M2, so never used on autos, where 5% of that is the norm.
Acceptable to most, but in harsh climes like Australia, simply not good enough, and it takes a bit of work to keep your auto finish ,er, up to scratch.
Whether you choose to do the work is entirely up to you.
My old BMW G/S just doesnt look right without the grime/patina it has accumulated on a couple of (3/4) RTWs, and 55 years/ 500,000 km.
But the little toy Hima seems to need a pretty up regularly, dirt grime and hard use just don't seem to suit it!