Well my suggestion isn’t strictly a racing game but I don’t really get latched onto traditional racing games around a handful of tracks where you repeat the same course over and over again.
I like open world games where I can drive around doing missions or just cruising (think driving around in GTA vibes) and thus Motor Town is by far my favorite singleplayer and multiplayer racing game currently especially for the deck and especially because of its low-poly graphical style keeping graphics performance reasonable even though it is the unreal engine under the hood.
https://store.steampowered.com/app/1369670/Motor_Town_Behind_The_Wheel/
The tire physics make throwing a massive engine in a car and ripping power slides at 80 mph a blast. The driving just feels damn good, the only games that beat it are BeamNG and maybe some of the bigger racing games like Assetto Corsa or iRacing but I don’t know I haven’t played those because in those games I can’t buy a box truck, throw a v12 in it and drive around like a mad man delivering packages, then abruptly decide to go for chill vibes and do autopilot deliveries with my 18 wheeler, then decide to some urgent taxi jobs in my 4 door sports cars…
Seriously Wreckfest I think is the only other game that has felt in the moment to moment physics like I was driving a high torque real wheel drive high speed vehicle that can absolutely rocket around corners so long as the oversteer doesn’t get out of control and send you careening off the road. Mmmmmmm.
Motor Town has a the brilliant autopilot feature you can toggle on and off whenever you want which makes this the perfect driving game to play on a mobile gaming device like the deck because you can walk away or put the deck down for a second by just putting your vehicle into autopilot and treating the game more like an “idle clicker” game than a game that requires your constant focus.
No extensive destruction modeling in Motor Town, your vehicle definitely suffers damage in terms of performance being impacted from crashes but it doesn’t deform the vehicle like the detailed simulations of BeamNG or Wreckfest. That isn’t that important to me for this type of game though.
Speaking of car crashes, Rigs Of Rods I think deserves a mention here too especialllly since it is open source!!. Yes it is old but it is still being actively developed (albeit at a slow pace) and that age makes it run fantastic on the Steam Deck. I wouldn’t suggest Rigs Of Rods as a replacement for the other racing games suggested in this video, but the sandboxy vibes of Rigs Of Rods are ideal for a portable device like the Steam Deck where you might want to play a game that doesn’t require you to do anything but mindlessly smash cars into walls as fast as you can lol.
It also is worth mentioning, a whole lot of people have put a WHOLE lot of effort into making detailed cars for Rigs Of Rods. Apparently a decent amount of vehicles including stuff like Dakar rally style off-roading heavy duty trucks didn’t make it into BeamNG because of the conundrum of moving donated work to a monetized game.
So this isn’t some empty game with no actual significant body of quality modded content, there are a lot of toys in Rigs Of Rods worth playing around with.