I don’t know much about this, but from what I understand, the manufacture of medicinal oxygen is very complex and its transportation very dangerous, as pure oxygen is highly flammable (as one would expect).
This is a quote from BBC:
Typically, healthcare facilities consume about 15% of the oxygen supply, leaving the rest for industrial use. But amid the second wave in India, nearly 90% of the country’s oxygen supply – 7,500 metric tons per day – is diverted for medical use.
Here are the complications of dealing with oxygen:
Liquid oxygen, pale blue and extremely cold, with a temperature of about -183 ° C, is a refrigerated gas that can only be stored and transported in special cylinders and tanks.
Oxygen tankers often line up outside a plant for hours and take about two hours to fill one tank. These carriers take several more hours to travel to or across different cities within the states.
Carriers also have to follow a certain speed limit – no more than 25 mph (40 km / h) – and often not travel at night to avoid accidents.