It’s the most critical, most basic factor in determining what software to choose. I am specifically using software that works on plain-text Markdown files for many reasons, least of all that I need other software to be able to interact with those files. You can’t do that with Trilium.
Secondly, Obsidian does not use its own linking system, it supports both the widely used Wikilinks system and the DaringFireball/CommonMark markdown system.
Come on. At least have knowledge about the software you are trying to criticise.