If you drop the plaintext requirement (which IMO is anachronistic, if not for the necessity to fend against a potentially turning hostile developer in a close-source set-up), you may find https://triliumnotes.org/ liberating.

If you must stick to the "notes as plain text files" paradigm, siyuan is better than obsidian in about every aspect, and logseq in other, more niche ones. Trilium is better than them all (IMHO), being the only one that does "note as data" correctly and efficiently (you don't have the same data model divide like seen in notion between notes and databases).