What blockchain doesn't have high transaction costs once it scales up to large usage? Fundamentally blockchains are about hyper-redundant indestructable storage with expensive costs for writing to that storage to prevent flooding it with garbage. The most mature and sophisticated blockchain that doesn't involve burning down a forest to solve sudokus is the Ethereum network, which is probably the one to point to when we're talking about a large blockchain, and that's one that uses the subcurrency of "gas" to model paying for recording into that ledger.

Are there any blockchains that could handle transaction volumes on the scale of a game-store like Gog or Epic (much less Steam) without putting non-trivial prices on writing the transactions to the ledger?