That is a feature, not a bug: it means that candidates know that jobs they see posted on that site have actually been at least looked at by the actual team you'll work with. Filtering out jobs offers that are just HR buzzword soup would be exactly its competitive advantage over Indeed and LinkedIn job-spam.
> hoping that they can't reverse-engineer the solution before you catch up
Don't worry; they can't. Kodak couldn't even pivot to digital and they invented digital photography! Huge companies have awful, terrible, very bad, no-good software, and leadership that has no interest in ever adapting to anything. Besides, the niche is different anyway.
> "why would I feel motivated to complete a long profile when I can just spam my pre-made resume, since it will be required at some point in the future anyway."
Because you're catering to applicants who are picky about what job they're looking for. I don't just want any job -- the list of jobs I'm qualified to do is vastly, vastly larger than the list of jobs I'd ever want to do.
You're not trying to replace Indeed: you're trying to replace recruiters.