I've used the Bullet Journal style for several years now. I agree with your appreciation for simplicity. You don't need a special journal made just for Bullet -- you can use any old notebook. You don't need to spend a lot of money. You can just get started. I find handwriting/logging my work & events and noting key conversations & meetings is extremely helpful. I think of it more as a log that a journal. When tasks pop up, I often toss them into my todo app so I can better organize them.

I also love the flexibility ... tossing in a page to start a list of side hustle ideas, book recommendations, or blog posts. It helps me to offload all these my great ideas, even if I never act on 99% of them.

In all these years, I haven't found anything that beats this format. Not even close.