It sounds like there might be a larger project management issue within your team, though it’s hard to tell from a single example. Features should solve business problems and should come from your clients and/or users and not from engineers. Are your users complaining about your static solution? If not, then why change it? Engineers should work on things that will add value to the business. Arbitrary performance improvements and code rewrites that don’t solve any business issues should be rejected by your project manager.

My suggestion would be to bring this to the attention of your PM. If that fails, then focus on picking up tasks of high value and visibility. Let the “smart” engineers do code rewrites or performance improvements. You’ll have a lot more to show on your resume, feel a greater sense of accomplishment in your work, and will have a greater chance of getting noticed as a star on your team.