You can open these files with any text editor. They will look exactly the same as they look in Obsidian.
Obsidian doesn’t do anything strange to your files. If you want to keep things highly compatible you can do so without any problems.
Like you said:
myfile
would just look like
myfile.md in your files
Just give it a try and you will see.
Create a new vault, add some files and wherever you store them in your file system you’ll have access to them and you are free to open them with whatever text editor you like.
Let us know if your question is solved, to mark it as resolved help!