Do you need blockchain for smart contracts?

In the realm of cryptocurrency and finance, the question of whether blockchain is necessary for smart contracts often arises. As a practitioner in this field, I'm curious to delve deeper into this topic. Blockchain technology, renowned for its decentralized, immutable ledger, has been touted as the backbone for smart contracts, enabling self-executing agreements without the need for a third-party intermediary. But does it really necessitate the use of blockchain? Or are there other methods that could potentially fulfill the same objectives? This query aims to uncover the nuances of this discussion, examining the merits and potential drawbacks of using blockchain for smart contracts.