I skimmed through the linked articles and I generally agree. I understand that fear I also was there at some point and I also got stuff stolen from me in the past (some guy traced my artworks and then posted them without credits) but really no body cared really. The tracing was so bad and I only found about it because I lost the original as searched online for it through a description of the image and then found the copy. It only gets nasty when someone thinks you are actually the copy cat but that never happened to me once, most people see the signature date or upload date and are smart enough to figure it out.
Ideas are rarely original enough to be worth protecting
So this might sound harsh but most ideas are not that great, really. The idea of “Orphan boy finds out he’s magical all the time and goes to magic school” was not invented with Harry Potter it has been there countless times. There are countless of “teenage group goes missing in forest and then Zombies”, countless “child gets sucked into TV/Book/Phone and enters fantasy world”, countless “aliens invade earth and get pushed back buy an unlikely event”. There is a good chance that when you enter your idea on https://tvtropes.org/ you find it a dozen times, even altered, inverted and subverted.
Ironically a lot of people (I see this with writers more often than with painters) will often have great ideas but then don’t make the thing because “there was already something similar” and this is a real loss in my opinion. Imagine Tomb Raider would have never been made just because they thought: “Oh this is just Indiana Jones but with a Women, and Wolfs instead of Nazis.” It might never was on the same level of popularity (Although in recent years Tomb Raider catches up again) but that didn’t stop em to do it anyway. Same thing with Giana Sisters and Super Mario (and Giana Sisters really started out as a blatant clone of Super Mario bros)
An Idea alone is worthless
Back in the 1400s many people already had the Idea that maybe you could get to Asia by sailing west for long enough but that idea by itself was not worth anything until someone strapped its belt and actually did it.
Everyone can have an Idea but what is important is what someone makes out of it and someone without creativity would likely be unable to do anything with your idea. Someone with lots of creativity most likely already had a similar idea and will make something completely different out of it.
So even when your Idea gets stolen, it is not really gone, you still have it you can still can make your own thing of it. It’s not like when you car is stolen it’s not in your hands anymore. Perhaps you really get unlucky and someone else made something more popular out of the same idea but perhaps they were just better then.
“This is my OC, pls don’t steal”
This is a popular meme for a reason. It often also makes fun of the originality of Original Characters often being overestimated by their creator. It is the same with general ideas, rarely wasn’t something explored already but it really doesn’t matter if someone had the same or a similar idea already.
The take away
So ultimately you should not worry so much what other people could make with your ideas (easier said then done, I know), Most important is what you made out of them. If someone else finds it and makes something better of it, well maybe they also went an extra step, and that’s fine. Or the build on your work, that’s fine too. I bet you also build a lot on other people’s ideas.
Ideas are meant to be shared
Meanwhile I like sharing my random ideas with anyone who likes to hear them. Sometimes they have an even better idea inspired by mine which they tell me about and improve mine. Sometimes someone else thinks it’s great and does something with that but that’s okay. I’m working 40 hours a week on coding and I don’t have that much time and energy anymore for doing art, like I used to be. It’s cool to see my idea at least not got to waste then.
Sharing ideas is the very principle the public internet was once build on, before corporate greed ruined it, and we should not let them take it away from us too. There rarely is a billion dollar idea (especially in art) and when you have it, you most likely know it too.