I've always kind of expected it to work this way, with people being cutthroat and stealing credit for other people's work.

What I have seen in reality is a lot more nuanced. There are a lot of good ideas that will simply die if nobody pitches them the right way, i.e. if no one gets the rest of the team/org/company to understand and agree that it solves an important problem.

There are also very few novel ideas in a mature business or technology space. Every time I think I've come up with one, I search the internal company docs and often someone had mentioned the same thing 5 years ago in some long-forgotten design doc or something.

I've come to realize that the hard thing and the bottleneck for a good idea to have real impact is not the idea itself or the execution, it's pulling the right strings to make space for the idea and get it accepted. At a small scale, in your own team or ownership domain, this isn't necessary and you can just build things and let the results speak for themselves. But the amount of impact that thing has on the broader company will be limited if you don't pull the strings the right way.

Some people despise this idea and in that case, a big company is probably not the right place for you. But most of the cases I've seen of "brilliant engineers passed over for credit" were people not realizing and not doing this necessary part of the job. If someone else steps in and gets the idea more widely recognized after you had let it stall and moved onto the next thing, then 1. usually you do still some partial recognition for it so it's a win/win and 2. the other person is not really stealing credit, because if they had done nothing the idea would have just died and you wouldn't have gotten credit anyway.