The point about the 'success' of novelty acts - and that is what they are - like Lost Voice Guy is simply down to circumstances.
If you are beamed into the homes of millions at peak time on a Saturday night, even if you are banging your head with a tray singing Mule Train, you are going to achieve an audience, and some media coverage, which some will interpret as 'success'.
But when the show is not on any more, how many of those people who sat and thought you were vaguely different on their televisions, are going to stump out twenty or thirty pounds and drive to a theatre and park the car on a cold winter night, in order to watch you do what you do in a live setting?
The answer is - a fraction of your original audience, and that is when your 'success' evaporates.
By definition, novelty is fleeting and forgettable, and that is what the majority of TV 'talent' shows actually show us.