P2SH introduced the concept of sending BTC to a script’s hash instead of a public key hash. The spender only reveals the full script when they spend, preserving privacy for more complex scripts (like multisig). It shortens what senders must see or handle—just a single hash. Then the real logic (multisig or otherwise) is revealed in the spending transaction. This setup facilitated easily shareable addresses for complex scripts (like 2-of-3 multisig), as recipients don’t need to broadcast the entire script upfront. Bech32-based P2WSH offers a native SegWit version, but P2SH remains widely used for multisig wallets.