You're assuming the text editor component alone took 8 months, but of course it did not! That would be crazy. There's a whole app built around the text component, which is what took my time, and the reason people are buying the app.
Development is ongoing for the features around the text component. I added folding lists which took a while, and because I offer outliner features I added focus/hoist which was also quite complicated.
Performance profiling and adjustments were measured and solved when I was almost done, because premature optimisation is a bad idea.
I don't consider what I did fighting any sort of limitations, so I guess it's a point-of-view thing. I wanted to use system components, and the only way to do that whilst maintaining performance is to do it with due care and attention. Nothing comes for free.
Nothing comes for free, but OP’s entire point is that the price to pay for even halfway decent native markdown rendering is too high - and thus a reason why people often give up and go to Electron.
They could not have made their point more clearly but people like you are up and down the thread wanting to call “skill issue”. The reality is that nobody gives a shit and they want to ship interesting things fast; if OS makers won’t get the hell in line and offer APIs to do it, then these developers are going to just pick Electron.
Life is way too short to sit down and write half a damn text editor when all you wanted to do was shit out a basic application with blobs of markdown.