I've settled on markdown with optional linking semantics. I've bounced around between the various popular apps, but having plain text files at the end of the day is important to me. I was quite happy with logseq and abandoned them as soon as they decided to invest in a database first model. Fortunately all of my notes were mostly just markdown and migration is relatively easy. In the era of LLMs I'm not really using a dedicated notes front end. I've got a notes system which includes the ability to add things to Family Apple Notes and Apple Reminders under various categories. My "LLM Assistants" can read my Apple Notes and Reminders so that's the way I stay in sync on most devices I own.