Great MJK, sounds like a blast, and a positive experience...
Yet you brought up a point that I don't know many have gotten into in here yet. Point being, in audio circuits, it's not just a turntable, tape deck, CD, or device that matters, it's the whole chain of components, and the end result is what we hear out've speakers, yet that's only part of the equation...
A vocalist uses his voice--->microphone---->amp------>speakers---->room acoustics similarly... I'm sure equipment does matter. Assuming I could sing, I WOULD care to learn which microphone is best suited for "me", given aspects of my style. Microphones capture sound in different ways, and have their own characteristics too. Assuming I were pro, I'd likely want to narrow down the microphones I use when performing in certain venues... Reason being, even when mic'ing amps, and guitar, there's a big difference in just the Shure SM-48, 57, 58, 5655, etc
Yet this goes over and beyond most Karaoke apps.
Interestingly,it appears that there's close to a 50/50 split in the "tone is more the performer" vs the "Tone is more an aspect of the electronics used" ongoing debate..
Constantly you hear in musician circuits.. "Tone is in the fingers and soul of the artist" vs "No it's not, the pickups of the guitar, tube amps, even cable and how stomp boxes are wired is more important".....the ratio of which is which is always debated.. Naturally I believe it's both...but that makes me a fence sitter...