Are rims important, yes are they the most important part on the bike...no.

I typically run 36 hole 3x hand built wheels. Components vary depending on the bike. I prefer box section rims with eyelets and 14 ga stainless steel spokes. My favorite all around rim is the Sun CR-18, best bang for the buck that I have found. I run them in 4 different sizes at the moment. I also have a couple sets of Sun Rhyno Lites. The other bikes have whatever came on them from the factory, ranging from pure crap to must be good it has lasted 40 years.

A properly built and tensioned wheel IMHO is more important than the actual components. I can take middle of the road components, hand build and tension a wheel and have it out perform and outlast a poorly built wheel of top shelf components. FWIW I have seen bikes that cost over $2,000usd that had wheels that were in such poor shape that they were all but worthless. I have an all steel wheel on one of my old Raleighs that I rebuilt years ago that is still chugging along after 35 years of abuse and around 30,000 miles. It could stand to be replaced the chrome is pretty well worn off the braking surface.

Aaron