I think the first time I tried N64 emulation must have been in late 2002. There were indeed still games released for this system at the time, although not many. Tony Hawk's Pro Skater 3 (ported to the console in 2002) was one of the last big games for it. Fun fact: The PC version at lowest settings looks almost identical to the N64 port.
Early N64 emulation was spotty, but the fact that it worked at all absolutely blew my mind, especially since I was just in the process of switching from N64 to PC as my main gaming platform. Super Mario 64 was one of the first titles to be properly playable with next to no issues, but outside of that game, it was a bit of a gamble and remained so for years. Performance could vary wildly, glitches were very common (some titles remained unplayable until surprisingly recently, like the excellent voxel-based Command and Conquer port for the system) and the plugin system proved to be a nightmare, as it fractured development resources.
I experimented with this as well, but since I was keeping full copies of the discs on my hard drives anyway, it was unnecessary in my case. I still have most of these disc images; now on my NAS.