In computing and engineering, almost all "new" developments are actually variations or recombinations of things that have already been done.
BUT it's not just computing! That is also true of all the other arts, crafts, literature, music, ....
There is nothing wrong with this! It can be fun and rewarding to experiment this way, and some of the variations and recombinations are sufficiently novel and/or valuable that they are taken up by others. You just have to try the experiment and see where it goes.
An interesting form of variation is to remove something, or revert to something that was almost abandoned years ago. There have been a number of interesting projects recently that do this - the uxn virtual machine, the Gemini internet protocol, even the SerenityOS operating system. All three of these projects have attracted many developers besides their original authors.
Another form of variation is scale. Pick something insanely ambitious -- that seems to require a huge corporation -- and scale it down so you can do it all by yourself. The marginalia search engine is created and operated by one guy and runs on a computer in his living room.