Currently it's unknown if Curiosity is being driven with a Steamdeck as of this moment, but it's definitely possible if the one here on Earth can be controlled with one :D

Curiosity rover simulator when?

34 minute latency, literally unplayable

It's not often that I downvote anything posted to this community, but I've done so here. A few notes of caution about this article are required:

• It contains no mention whatsoever of Curiosity, Perseverance or any rover currently scheduled for launch to Mars, let alone one currently operating on the planet
• The time delay for signals between Earth and Mars is currently ~17 minutes - that's one way - and is never less than ~4. I don't think thumbsticks, face buttons or a handheld screen are going to mitigate that. Your refresh rate is going to be just a bit short of 60 FPS. Unless the Steam Deck/tablet/PC can violate relativity.
• Remotely operated ground vehicles on other planets (with the possible exception of Luna) are semi-autonomous, in the sense that they drive themselves to locations that the scientists direct them to. Geologists choose a point in the landscape where they want to the rover to go, then the rover chooses a path through the landscape via image analysis. Rover "drivers" (AKA Rover Planners) can issue a "directed drive" command, i.e. manually pre-planning the route, but the autonomous capability ("AutoNav") is commonly used for longer drives.
• We are not in continuous communication with any Mars rover, lander or orbiter. Interplanetary communication for landed vehicles works like this: Rover uploads to Mars-orbiting satellite, via its weak transmitter --> Mars-orbiting satellite transmits to Earth, via its stronger transmitter --> Absurdly powerful ground-based receiver on Earth captures signal --> Data packet from rover is transmitted to control center. In the case of uploading commands, the sequence is reversed. Please note that all of this requires the satellite at Mars to actually pass over the rover's location, preferably directly overhead (not always the case). This entire sequence can happen, at most, a few times a day, but generally it happens once or twice.
• Using handheld devices to plan the rover's route (in the case of the engineers) or review the rover's data and photos (in the case of the scientists) makes little sense. Larger displays are clearly better for this task, where mapping and visualization are essential. The complex software suites that the engineers use to plan the rover's drives aren't going to be better suited to a video game controller than they are to a mouse and keyboard.

In short, the suggestion that a handheld gaming device would be used for operating a currently active spacecraft, lander or rover is absurd.