Tuna from the ocean at large may be a "commons", sure, but helium comes from natural gas deposits, which tend to be in areas where one nation or another claims

Tuna from the ocean at large may be a "commons", sure, but helium comes from natural gas deposits, which tend to be in areas where one nation or another claims exclusive rights to said deposits, treats them like property, and seeks to maximize the value they can extract from them (while still competing with other resource-holders in a market).