If someone is not highly skilled and works low end jobs, he could be left jobless if minimum wage increases. Some businesses already have low profitability and they can't absorb an increase in minimum wage.
I know where you are getting from but I don't see a simple solution. UBI might help but from my perspective the cost of UBI is too large to pull off in any normal economy (petro states in the gulf can probably pull it off).
Social safety nets is another thing that needs to be improved though. I don't believe in UBI myself, I think (and I'm not an economist) that the cost of living will just go up by an equal amount, negating the whole thing. It seems to work on a small scale, but cost of living is not changed significantly if only a small section of a country receives UBI.
Anyway, back to unemployment, in theory automation causes unemployment too, but in practice, while people lose jobs over automation, the overall unemployment rate is not significantly affected. Or in other words, there's always more work to be done.
If you made this argument 100 years ago I might be inclined to agree with you, but "reasonable" minimum wages (i.e.: a 40h/week job pays always enough to feed a family and a roof over your head) have been tried and tested in countries all over the world and as far as I'm aware, they're almost always a success.
The 'low skill worker' losing job opportunities because of too high minimum wages is a myth that just doesn't hold up to reality, no matter how many times conservatives afraid of losing their own bottom line or relative status repeat it.
If you take it to extreme, it's obvious it's not a myth. Imagine a 100k USD yearly minimum wage. Obviously all unskilled worked wouldn't be able to earn this much for the employed, but in places where you have to have someone do the job, they'd enjoy their new high minimum wage.
A few quotes here:
> Starting pay for the humblest burger-flipper at McDonald’s in Denmark is about $22 an hour once various pay supplements are included.
> Americans might suspect that the Danish safety net encourages laziness. But 79 percent of Danes ages 16 to 64 are in the labor force, five percentage points higher than in the United States.