Sorry for the very late reply.
Indeed, I still stumble over the lack of folder structure as in OneNote or similar are. At the same time, I am beginning to love the possibilities of the daily log, in conjunction with the tags.
In the last few days, the purpose of graph view has really become clear to me. Until now, I had always considered this only as a nice gimmick.
Until I have arrived 100% at LogSeq, I still need some time. With your answers I got much further and understood that a sidebar is not necessary and probably not possible.
Thank you!