I'm not well versed in things like airflow or cooling, but more than a few people struggle with performance issues despite meeting minimum or even recommended specs because they don't know how to properly care for their hardware to keep temps under control.

A guide pushed by Steam itself to users could help with this incredibly well. At present it's mostly up to users to hunt down information on fixing their issues on Reddit or other forums, which is sometimes a bit daunting, leading to frustration and possibly settling for worse performance. Even a small change like adjusting airflow, reapplying thermal paste, or just blowing out your fans can lead to lower temps and thus improved performance, even for people that don't have overheating issues. If Steam itself pushed a comprehensive and highly visible guide that can diagnose and propose genuine fixes, then a lot of gamers could get varying but significant amounts of increased performance.

Guides like this exist elsewhere, but people have to go out of their way to find them. A guide pushed by Steam could help a lot more people due to the visibility and credibility of the platform. Steam has these in great enough quantities that such guides would be easy to point to or find for users that operate on other platforms. The catch is that it has to exist as something external to existing guides or the forums, like a guidebook format, something that can show up as like a popup or as a prominent section on the store page. This would help to educate people and improve their experience in games without having to buy expensive new hardware, or even to get more out of their already expensive hardware if they don't realize that other elements of their PC are stifling said expensive hardware.

This is also beneficial because it can help developers more easily parse feedback to determine what are issues caused by their game and which are due to users not getting their full performance from their hardware. This is less to give developers with performance issues a pass and more to help them diagnose and correct issues more quickly and easily.

Gamers are often eager to help diagnose and fix performance issues that this guide could fix, but I feel like it would be good for Valve (and other platforms) to use their influence to take some of this responsibility and help even more people that don't know all of this and are overwhelmed by hunting down the information