I use a memory palace and a system of mnemonics all the time for things I want to commit to long term memory. I can speak Japanese and read 2,000 kanji thanks to memory palace techniques. Still, the cognitive load for scribbling down a grocery list is much smaller than trying to make a memorable grocery list in my memory palace. My memory palace also doesn't help me when I've mindlessly set my wallet down and can't find it 30 seconds later. I guess I'm saying that I agree, it doesn't replace note taking.