A CD Projekt RED dev warns players that, as of its 2.0 update, Cyberpunk 2077 may be much harder on their CPUs than before.
The game will actually use all of the CPU cores without mods now. The lack of SMT support has been fixed, that sounds like optimisation to me. Currently, the game is struggling to use more than half the available CPU power available on some systems.
You can still artificially limit the CPU to only half your cores, of course (by setting the task affinity for the game process)