As long as I knew it wouldn't make identifying me easier, I'd report the true value, since I think it's a good way to improve the awareness of software engineer

As long as I knew it wouldn't make identifying me easier, I'd report the true value, since I think it's a good way to improve the awareness of software engineers as a whole (especially if most of us do it). Better informed actors can negotiate better. The only scenario where it's better to not disclose it is a one where I think I'm already making more than my worth (than I should, according to the market). Companies look down on sharing this information, because they have nothing to gain from it (or at least nothing easily measurable, and presentable as a gain to shareholders). Or am I missing something?