When asserts folder is getting bigger, find the appendix one page is difficult. If logseq support URI or URL inkk for local file, then can manage files more effective.
Logseq is already using relative links in Markdown format.
By default, since pages are under /pages, when referencing an asset it will be [](../assets/example.png): those first two dots means “exist from /pages” (because it’s where the Markdown file you are editing is) and then /assets/ means look at the subfolder assets.
But you can move pages and assets freely in your graph folder but you need to update the references accordingly. Logseq still doesn’t provide a built-in file manager that updates references automatically, but for that you can use VS Code or Obsidian: move .md files and assets with their file manager and you should be prompted with a confirmation dialog that ask you if you want to update references accordingly. Logseq will simply respect those changes.
Also take a look at macros for assets management: