Maybe for you. For myself (a professional data scientist) and every other professional data scientist I have worked with, notebooks are useful and better than Windows Notepad, otherwise we would all be using Windows Notepad.
This is such a strongly worded post that I have to wonder what exactly you are trying to do with notebooks, that makes it not just suboptimal but atrocious. Because it sounds like you're using it for something other than its intended purpose, in which case of course it's atrocious, because you're using a tool for something other than what it was designed to do.
If you think of a notebook like a tool for literate programming, then sure, I can see why you might have issues with them. They don't integrate well with text editors, other tooling such as test runners, or even the Python import system. I would strongly recommend against writing a library in Jupyter. I would strongly recommend against writing low-level CUDA code in a Python notebook. I would weakly recommend against writing production ETL pipelines in a notebook (although if your ETL pipeline is just untested spaghetti code, you might as well do it in a notebook).
Notebooks are not competing with IDEs, text editors, or any other dev tooling. Notebooks are an alternative to REPLs. If you use a notebook like a super-powered REPL, you are going to get a lot out of it. I can't think of a single complaint about a notebook that can't also be leveled at an "Editor+REPL" type of workflow, and I can think of many problems with the Editor+REPL setup that are solved by notebooks.
If you prefer using Spyder and RStudio with the console and plot window, that's great. I honestly do too. There is a lot to dislike about Jupyter Notebook and Jupyter Lab specifically. But notebooks in general, and Jupyter specifically, are still the most efficient tool I've found for doing something, keeping track of / taking notes on what I did, and displaying the results in a way that I and my colleagues can easily understand what I did.
There are also other notebook formats such as RMarkdown and Pluto, both of which have much nicer plain-text representations than Jupyter Notebook. I'm a big fan of those, too. But there are tradeoffs in every design and I'm not about to malign the Jupyter project (or its ancestor IPython) for its choice to use JSON.