Galaxy Research recently reported that Bitcoin faces severe challenges as a data availability (DA) layer. The main points are as follows: Scarce block space: Bitcoin block size is capped at 4MB, and the data published by ZK-Rollup every 6-8 blocks may occupy 10% of block space. High cost: At a rate of 10-50 sat/vByte, the monthly data publishing cost of Rollup is about $4.6-2.3 million. Economic feasibility: Rollup needs to process a large number of transactions per month and charge enough fees to be profitable. For example, at a monthly transaction volume of 20 million, each transaction fee needs to be $0.05-0.23 to break even. Increased competition: The introduction of Rollup will increase competition for block space, which may push up transaction fees for all users. Alternatives: If the cost is too high, Rollup may turn to alternative DA layers such as Celestia, or build L3 solutions. Security trade-off: Using Bitcoin as the DA layer is costly, but it provides unparalleled security and decentralization. The report believes that only a few Rollup projects can survive on the Bitcoin network, and recommends that projects explore strategies such as cooperating with miners and developing fee estimation engines to improve profitability.