I’ve built lots of applications without code (and teach others how @ https://www.makerpad.co/) one being a mini Netflix ‘clone', Airbnb ‘clone’ and Fiverr ‘clone’.
They may not be able to withstand Netflix level of users and usage but why should every startup/business have to aim for that. It could service hundreds/thousands of users and turnover great revenue for those running it.
while very valuable for learning, i find that folks building thematic maker sites (no code, react/node, rails, etc.) are very biased towards their own way and often haven't made a "real" product built on what they profess.
engineers would be better off using "no code" more often, and non-engineers would be better off learning just enough react, python, etc. to ship something.
otherwise, everything begins to look like a hammer.
The only reason these tutorials are built as 'clones' is to show the features for others to tweak for their own.