I legitimately don't understand this sentiment. If cloning software is really as easy as you say it is nowadays, the only difference between our own agent stack, the small scrappy indie devs, and commercial software companies, is who pays for the tokens.
Assuming this, I see even LESS of a reason NOT to have a wide array of open versions we can all hack our way from. We'll collectively have to invest less if we have an open base to work from. Reinventing the wheel doesn't stop being reinventing the wheel because an LLM did it.
Obsidian isn’t hard to code. That was never the barrier. The barrier was that the creators took a risk and made something new with their design choices. LLMs (at least today) can clone and mash-up but they don’t make new choices. Open source as a whole is a lot better at copying than creating. Happy to be corrected but all the major user apps I know of are clones of commercial products.