The most obvious answer to this question lies in the development dynamics of LSDFi and LRTFi. Projects like Lido, Rocket Pool, Stader, and others once offered users the ability to maintain liquidity for assets staked in Ethereum. For a long time, LSTs were primarily used in DEXs, lending platforms, and other DeFi protocols in fairly limited scenarios. The term LSDFi itself emerged around the 2022-2023 transition period when protocols aimed at utilizing LST began to appear. Looking at EigenLayer in this context, it resembles Ethereum – the protocol itself doesn't offer liquid tokens, so LRT protocols quickly emerged in large numbers, following a model that had already been tested with LSTs.