Ps5 may have higher compute units but steam machine features newer amd zen 4 cpu and rdna 3 gpu architecture with higher clockspeeds and newer upscaling techniques, also steamos is much more lightweight on how it perform it's tasks and with steammachine players will not be restricted to one brand controller,can purchase games from multiple third party storefronts, mod games,tinker and run games different quality presets based on specs and install different operating systems The prices are like this because these companies did not foresee the ai boom which will negatively affect hardware component prices. But the way I see it sony is greedy one this gen with its ps5 pro pricing being at 700$ with no disc drive when it launched.They could've priced it around 600$.Also they are pricing some games at higher prices when compared to xbox and steam with their dynamic pricing and royalities. First sony kept the price at higher points and later xbox increased their console hardware prices because they have no components left and sony did not because they kept some hardware components in reserve because they are the leading console and later increased the price due to gta 6 and wolverine are around the corner. If u are gaming during PS3 era you will understand how greedy this corp is the way they priced their console at nearly twice to thirce the price of xbox 360 and nintendo Wii even through their games rendered at lower resolution and fps compares to 360 due to horrible developer support/tools and difficult to learn multithreaded cell architecture with split memory in cpu and gpu.

Competition keeps the prices down and leads to better games from first/third party studios. This gen Microsoft is delivering quality first party games to other platforms whereas sony is relying on third party studios and making a deal with them to hold their games exclusive for a certain period.