At some point developers seem to forget that making stuff is fun. The fact SQLite and GCC exist doesn't mean you're banned from making a database or a C compiler.
You're allowed to make stuff just because.
What an incredibly blinkered view. You think there's no value at all in making software unless your program solves a truly novel problem, and does so for millions of users?
There's so much joy that can be found in simple, disposable acts of creativity. I don't need the world to applaud when I cook an omelette, make a table out of wood or play a piece on the piano. Why would I need that from the software I make? Just because you can buy a table from IKEA doesn't mean its not fun to make one yourself. Just because someone on spotify played it better doesn't mean there's no joy in playing music.
Why would I hesitate to make my ideal photo library program, just because other programs exist? What a sad, self-limiting rule.
Does that make you mad? Why does other people enjoying themselves with LLMs make you mad?
You can accomplish most of that by installing Syncthing.
But the objection is that you’re not really building anything new even if you think it’s a new idea. By your definition you’re building for yourself and not sharing…so what good are your little projects. Reading your original list it just seems like you want to build and run software without having to do any research, even if a solution already exists.