I think you meant [forward] slash (/), not backslash (\) 
For those wondering, this is how inserting ‘slash commands’ looks like in Notion:
Edit: For context, the previous two and my comment were just merged into this thread - I hope my image wasn’t superfluous at that point 
@Ehsan made great points why and how this would be a great addition to Obsidian’s current options of insertion. I’m all for ‘native text expansion’.