For example, if the depth buffer is not needed after rendering, we can set it's STORE_OP to DONT_CARE so it doesn't get written back into main memory. Or maybe the color buffer needs to be cleared before being rendered to, but doesn't need to be read from, so we can set its LOAD_OP to CLEAR, which has a small overhead but not as much as loading previous color buffer values to SRAM.
The talk goes into more details, for example on how to get an efficient behavior when using MSAA (write back only the resolved buffer), and also how to do post-processing or shading from G-Buffer directly on-tile, without requiring reads/writes from/to main memory in-between.
The talk also touches on Vulkan pipeline barriers, which are useful to avoid pipeline stalls in-between draw calls. For example, there is the "Bottom to top" pipeline, where there is a barrier between each render pass (the next pass cannot execute before the current one is finished):