A Galaxy Research report has suggested that most Bitcoin layer-2 scaling networks, particularly “rollups,” may not be sustainable in the long term despite their popularity as a promising method to keep Bitcoin payments cheap, fast, and decentralized. In the report published Friday, Galaxy analyst Gabe Parker highlighted the cost of posting data as a fundamental challenge Bitcoin rollups face that post data to the base layer. Challenges facing Bitcoin rollupsParker explained that for Bitcoin rollups to thrive, they must generate substantial revenue from transaction fees on their own networks. T…