The 2% is the amount spent specifically on the Linux _Kernel_. The top 3 categories are:

- Cloud, Containers, and Virtualization: 25%

- Networking and Edge: 13%

- AI, ML, Data & Analytics: 12%

Also worth noting: 72% of the revenue is spent on Open Source Software, and 20% is Spent on Open Source Specifications. Full report is here: https://www.linuxfoundation.org/hubfs/Reports/2023_lf_annual...

I don't know what projects fall into those categories, but it's reasonable that supporting Virtualization and Networking could support Linux adoption and stability, without directly contributing to the Linux kernel itself.