Some of the best songs ever recorded have tone issues, straight up mistakes, flubs etc. One of the issues with todays music is it is too “clean”. Quantized to the click, perfect pitch correction etc. The human element has been all but removed. There are exceptions, but for the most part today’s music is just too sterile.
Yes and these mistakes and flubs largely go unnoticed by most listeners. A fan is absorbing the experience in its entirety, as a complete work of art. An incorrect change in tempo or flub is what makes the song unique to that band.
Regarding today's homogenized music and pitch control, it's ironic that singers are directed to sing "off key" or "flat" so that Auto-tune (using a square wave) can make those "electronic" vocals used in pop music.