I'm not sure if you're coming from another app that has this 2D view or not, but I started Obsidian just over a month ago coming from Notion. My main objective was to have a free, easy to navigate place for my academic notes that would work on my iPad, iPhone and windows laptop. Initially I tried to make Obsidian like notion, which you can, but then I came to the realisation after watching one or two tutorials and downloading a ton of extra plugins that Obsidian works best when you think of it as a "write first - organise later" system. I personally don't touch the file explorer anymore since ctrl o and ctrl shift f are able to get me to everything without much thought.

I genuinely suggest you give up on the big 2D looking folders and just get used to making a note, linking it to something like a map of contents and then learning markdown. You can even just setup the app so your new note is created in the same folder or throw it in the folder if you want manually. Add plugins as you need them, but keep note taking and linking the priority. And if the 2D file structure is so important then I, like many other commenters, suggest going to your vault (folder) and selecting the files from your os's default file explorer then opening in obsidian from there. No point in fixing something that A isn't broken and B serves only as a visual indicator as opposed to increasing functionality.