Depends on the finish. Unlacquered brass and nickel will tarnish. But nickel doesn't tarnish the way brass does. I have antique brass which has a protective coating, it hasn't changed.

I've had some cheap hardware that the finish wore off of.

Do most companies use a protective coating that doesn't tarnish?

I am purposely buying hardware that will develop a patina - unlacquered brass. If you don't want tarnish, look for lacquer or a PVD finish.

I would say that if you want unlacquered hardware you would have to seek it out, lacquered is much more common.

Is there one with a PVD finish?

I have called around and found none. Even Emtek does not have a PVD finish.

(I don't want unlacquered for sure.)

PVD might only be available for plumbing fixtures - faucets, etc. I only got familiar with the term because it was the *devil* trying to find fixtures that would age. You really do have to seek it out as most folks view it as a "defect" or a "flaw". Most reputable companies will tell you if the finish is "living."

Honeysucklevine...
I found the following at "Consumers Report".
The exterior of some faucets are bombarded with charged metal atoms that chemically bond to the surface of the base metal in a process called physical vapor deposition, or PVD. Different metals impart different finishes, including nickel and bronze. Faucets in our best faucets review with PVD finishes resisted our best attempts at scratching them. But corrosives like drain cleaner can stain them slightly.

I did find PVD for door knobs and faucets.

So far I called several companies and most said they used lacquer and it shouldn't tarnish.