This advice is only strictly true for AAA games. From what I've read from the more indie side of the games industry, there seems to be a common thread where the

This advice is only strictly true for AAA games. From what I've read from the more indie side of the games industry, there seems to be a common thread where the more time spent working on features for a game, the fatter the long tail became, and the spikier the stegosaurus tail tended to become. There seems to be advice that simply adding support for random steam features lead to sales (think things like trading cards, achievements, badges...). Language support can be a really unexpected big one as well. What's also counter intuitive is that porting games to other systems tends to increase existing sales channels. Now, it's not entirely clear from what I've read, if working on all these extended features for a game have the highest expected value, since it really is a hit driven industry, but they seem to be lower effort work, and are definitely worth it from a lowered risk payout point of view, particularly for a small dev shop that can't risk too many failures.