One of the most important stats for a number of indie developers is how many people are playing certain games. While you can check the top 100 games on Steam, it's hard for smaller developers to get an idea of how many people play less popular titles and genres. Being able to estimate those numbers can make it easier for them to make games that people will like, or garner funding from grant systems by proving that a game has a chance to be popular. But Valve seems hellbent on stopping that.
In a recent move it made Steam profiles private, effectively killing off Steam Spy's efforts at detailing game ownership. Developers then moved to tracking achievements to give a similar sort of statistic, but Valve has now made that impossible too. Achievement details were relatively accurate, but now Valve has rounded the number to the nearest decimal point (as per PCGamesN), which basically makes the data too inaccurate to use.
and yup they're rounding numbers now. looks like the gdpr thing was just an excuse after all
— Tyler Glaiel (@TylerGlaiel) July 4, 2018
While many initially thought that Valve privatised profiles to comply with Europe's GDPR legislation, it now seems more likely that it doesn't want third-party sales tracking -- for some reason. It hasn't released any kind of statement on the matter, but this arbitrary adjustment to its achievement system doesn't appear to have any other impact except on this tracking system. It seems vindictive.
Could it be that Valve is working on its own Steam Spy alternative? It has certainly hinted as much. You would have to wonder if there's some possibility of a claim for anti-competitive practices if it does so after forcing closure on other attempts at sales tracking.