Why isn’t CS:GO gambling considered as actual gambling?

Your intuition is not wrong. The gambling element in CS:GO betting is quite similar to traditional forms of gambling. However, the primary difference lies in the nature of the value bet. In conventional gambling, the player directly wagers hard cash or assets that can be easily converted into cash. However, in CS:GO betting you are staking virtual items (skins), which are not considered ‘real money’ by many jurisdictions, hence not classed as gambling by some legal systems.

That being said, the status of CS:GO gambling is somewhat contentious and depends on the legislation of a particular location. It’s not universally disregarded as gambling. Some regions and countries have ruled that because these skins have a market value – as they can be sold for cash – skin betting must therefore be regulated under their gambling laws. The legal perspective varies across different regions and hence it might not always be disassociated from ‘actual gambling’.