Here's a system that's gameable, but no
more gameable than other things our society seems to be fine with: have peers evaluate you for the quality of your work as opposed to your outputs. Retain people whose peers say "They do good work," even if they don't have a flashy success or novel discovery to show.
This is roughly how private industry works. I'm of course asked in job interviews about my successes, but the primary thing that determines whether I get a job, how much I get paid, whether I get other people to work with, etc. isn't what my past successes are, it's my ability to convince my peers that I am a steady and good worker. If I maintained some tech stack for two years, my employer is happy to let me continue doing that, and other employers are happy to hire me to maintain similar tech stacks, without me having been like the one person in the world to figure something out. (On rare occasion, I am, in the sense that I'll fix something upstream that's been challenging, and employers do value that! But there's no, e.g., "fix upstream bugs or perish" culture.)
As in private industry, it's gameable because it allows people doing poor-quality work to vouch for other people doing poor-quality work. But it's hard to game this long-term, because people interested in doing good-quality work will tend to find others who do, and in aggregate -- from a large number of such people working together over a period of time, not from any one individual -- these people will produce more measurable results.