it was a couple things. 1. It's really really hard to replace anyone's OLTP. 2. OLTP and OLAP are owned by such different teams. Who do you make your champion? 3. The modern HTAP dream is possible without something like SingleStore. You need a columnstore that can keep up with your OLTP tables and provide transactional correctness. Who cares if it's all within one system

ps: I worked at SingleStore. https://www.mooncake.dev/blog/htap-is-dead