Yes is true I agree, some jobs cannot be upgrade like you said. Hence pmw has a certification, resulting in barriers of entry.
Why I say MW is bad, is because it's a blunt tool, and it's mechanism is for the purpose of discrimination. If the objective is to lift poverty, you need to let peps be employed first and gain skills or savings , then they can accumulate capital.
We have to view this as a live and dynamic thing, not a static 1 dimensional model.
Some jobs just doesnt help you to gain skills or savings.
For example, hawker store assistant work long hours and draws little pay. It is physically demanding and tends to attract those without much formal education.
How would these people be able to go for upgrading when the majority of the time are spent in their work place? How could they accumulate saving when their pay is low in the first place?
So a solution has to be found to help lift them up, right?
It used to be HDB sell flats at low cost, then people can flip their flat to earn money which could be used for upgrading. But HDB has lost this purpose now due to its high price and policies.
Then, it used to be CPF can be used as a tool so that these people can retire with a substantial saving. But, after HDB price increase, and after CPF life/and all the compulsory plans, many are looking at no relief using their CPF.
It used to be that investing in their kids, getting a degree is a good investment. But now, there are lots of graduates not holding PMET jobs.
So you see, a lot have happened and it is mainly driven by policies of the Government.
What about progressive wage model (PWN)? It functioned like the min wage, but ties the wage increase to skills and certification. It is good, right? Well...
The 32,000 do not benefit. So the best way for Government to solve this problem is to implement PWN in these sectors if they are of the opinion that PWN > Min Wage. But why Government is not doing anything? If PWN cannot help, then what do the Government propose? Based on what I have seen so far, they proposed ... Nothing...
Is this acceptable?