They love this idea that mental health support can be provided by work and that people suffering from mental health disorders need to just take any and all jobs. No boss is going to be supportive of you having a mental breakdown once a week because you can't cope with what's being asked of you. You can exhaust all their EAP programmes and counselling etc. and still suffer because nothing about the underlying problem has shifted, so their only recourse left is to fire you or "manage you out". When reasonable adjustments become "special treatment" and the idea of "we all suffer with that, you just need to work harder to cope" seem to be the standard responses for getting help in work this is not a viable alternative to the welfare system.

If Labour aren't willing to come down hard on the side of ill and disabled workers in-work, punishing severely any employer that decides to fire a disabled worker during probation because they need 45 minutes to recollect themselves after a panic attack for example, then this is just ableist claptrap that will endanger the lives of people already suffering and struggling to find a place where they can even exist under capitalism.

Not to mention that the real reason the benefits bill is ballooning is because the state pension is a millstone around the political arm of the bourgeoisie's neck. This constant stabbing at working age people to constantly re-direct that one of the largest consumers of PIP benefit are near retirement age 55+ individuals who have been disabled by work and need help to reach retirement age to then receive PIP plus the state pension to survive. Completely unsustainable without addressing the root cause of the issue - that capitalism doesn't care how long their individual labour-powers last provided that there's always new ones to replace the old burned out ones, so it is happy to kill, maim and crush every individual over a life of soul and body crushing labour.