I have chosen to just remove years from copyrights/licenses.

AFAIK the copyright isn't invalidated by not giving a date; In fact I'm not even sure if a copyright notice is required at all.

Copyright years seem to be understood differently anyway. I've heard that it should be the beginning of the copyright, so there is no need to change it. The problem is that your copyrighted work is probably changing, so that brings up the question if those changes would justify a change to the date or not. I have also seen the format of "2013, 2015" or "2013 - 2015" using the first version's year and the current year.

It's all a big mess IMO

Under the Berne Convention copyright is an unregistered and automatic right - it took USA 102 years to ratify, until 1988. Prior to that in USA - as I understand it - one needed to register a work and put a copyright notice on with the year of registration. So it's a hang over from that really.

Having proof of the date of creation of a copyright work is useful - which is why print copy can still usefully have a date, but a © symbol as a claim of copyright is pretty useless except as a pseudo-legal claim (like a "shoplifters will be prosecuted" sign in a bricks-and-mortar store). A date might still serve as proof for a digital work that gets archived by a third party (like archive.org) but the ease of alteration makes it pretty poor otherwise.