The point of using markdown is to future proof your entire vault. Obsidian could disappear today and you’d still be able to access your vault without issues. Your vault is not reliant on obsidian at all. Your vault is literally a bunch of text files that Chromium (Yes Obsidian is built on the same browser that powers Edge and Chrome) interprets them as html in real time and connects in a specific way.
These connections are not unique to Obsidian at all. There are plenty of other programs that can relink these connections without Obsidian. You can even translate your .md files to html and open them in any browser as you see them in obsidian (as long as you save the obsidian.css or your own css file) otherwise it will look different. You can also convert these links to local file locations after you convert your files to html so you can literally browse your entire vault like a website in any browser.
Either way all your data is indepenant and stored in text files so small you can carry them around on a CD, from 1996. Oh and by the way Chromium is open source, the only thing unique to obsidian are the tools, plugins and gui.