Earlier quoted context omitted.
The point is you can't adequately judge whether a job counts as "wageslave" just from the salary. A $300K job where houses cost $2M is like a $30K job where houses cost $200K.
you are more than right, it is actually objectively worse. because $300K will demand much much more than 30k job. 300k job leads to stress, anxiety, performance calibrations, mental breakdowns, overwork, competition, lack of job security etc. 30k job could be very relaxed, could be part-time gig where you work few hours in a week. so work-life balance is really tilted worse for higher paying jobs
To be clear, it can be true, there are lots of stressful high paying jobs, my point is that it's not necessarily true.
I know low paid people with stressful jobs and highly paid people with less stress.