The share of incomes from private businesses (especially luxury businesses) isn't flat and benefits mostly the executives and directors and shareholders.
That isn't an argument for not breaking up a monopoly. Only an argument that the market may be big enough to support actual competition.
Why? Because the market is fragmenting to smaller operations who employ more people per unit of beer produced.
You can argue that from both sides, that it's less efficient vs generates more jobs, of course.
What is being claimed is that the majority of those employees are not seeing an increased benefit (wages) proportional to the increased profits of the company they work for, whereas shareholders and executives do.
If it were multiple competing companies, the same output would probably require MORE employees. One of the ways it is so profitable is to implement economies of scale not possible in a less monolithic industry.
You are failing to see that extractive business models such as monopolies do not add value, they extract value and concentrate it in the hands of the execs/owners. This removes capital from the socio-economic system/society and reduces the capabilities of the whole system to grow (the occasional purchase of a yacht does not rebalance things).