No no no no no. Design your product to be understandable at first pass. Apple famously doesn't do any of this with your iPhone, while Sony forces you to do it on every new device. Let the onboarding be a forcing function for usability. This isn't a crutch, it's something worse and damaging.
However, a B2B app ,which is where most product demo tutorials are used, isn't like this. Good product tutorials are great for salespeople to walk the customer through the app and sell properly to prospective clients.
When the contract sizes are in the 10,000s or 100,000s and the product is pretty complex then this is a good solution vs having your sales and support staff having to firefight issues.