A few examples of what is unreasonable:
Single parent in non-negotiable shift work.
PhD engineer cleaning toilets (I would also consider this an economically unreasonable waste).
A person who can work a maximum of 6 hours per day for health reasons (provable) should be sanctioned because they have rejected a 40-hour position.
You are indeed asking the right question, but unfortunately your own answer falls far short.
And personally, I do not want a single employee of the Employment Agency to decide whether someone is able to work or whether a particular job is reasonable for a given person.
First of all, the state should create more jobs before resorting to forced labor through coercion.
I do not want the state to waste resources (I mean time and personnel, not money) putting out a capitalist smokescreen before (actually I don’t want it at all) it tackles the Big Buckets (in the multi-layered sense): tax evasion, unjust tax avoidance (need for exemption review), and undeclared work (where again mostly the big players are relevant, the cleaning lady or someone cutting neighbors’ hair over the bathtub are simply unimportant).
Yes, the pensioner story sounds good at first. But it is just a smokescreen.
First, we do not have enough jobs! The skilled labor shortage is very industry-specific and in many sectors (automotive) the trend has already reversed again.
Precarious jobs are not affected by this at all.
But those who have worked their lives in these jobs (and are correspondingly qualified) are the pensioners who would even take up this chance. The highly educated engineers who are still needed in some areas no longer want to work and do not need to (financially). Those who do want to are not dependent on the €2,000 tax allowance to do so – they are intrinsically motivated, just restless.
Where the shortage is most glaring, e.g. care work, money is not the main problem but the inhuman working conditions. Someone who has retired from the job usually cannot do it anymore.
Next are the tax-free overtime hours. Again, first stimulate the need for the extra work.
How do you prevent loads of full-time workers then nominally reducing hours to part-time contracts and doing overtime on that basis (it may be that there are already approaches for this, but I think it is a legitimate question)?