Low learning curve, and in recent years better documentation.

Open source, continuous updates, community

I find Umbraco to be highly extensible and appreciate the great community around it. I also value the fact that it's open source, which makes it easy to debug, especially when using AI. Initially, it was considered as a temporary solution for us, but it turned out to be a great fit due to its extensibility and stability. The initial setup was fairly easy, and although we've spent time fine-tuning the developer experience, the startup process was simple.