Because a PC at a $700 price point will not perform the way the PS5 pro will, or be guaranteed that level of performance on its games for nearly as long. You can always get a better PC for more money but even at $700 the value to performance ratio is there for consoles.
Why not go PC at this point. Modern consoles are locked pre-built PCs and paying $700 for a locked system is crazy.
Steamdeck + Dock and you can game on your TV AND on your travels.
Because a PC at a $700 price point will not perform the way the PS5 pro will, or be guaranteed that level of performance on its games for nearly as long. You can always get a better PC for more money but even at $700 the value to performance ratio is there for consoles.