In fact, it is quite the opposite. Cardano allows many hundreds of transactions per block. Instead, it is accurate to say that Cardano allows a given transaction output to be spent a single time, by a single transaction, so protocols that give multiple people access to the same UTXO might face contention issues.

This fundamentally comes down to the shift in thinking from Ethereum, where you call into a smart contract to make it do something, to Cardano, where you lock outputs with a contract which then determines when the tokens locked in the contract can later be spent.