We have a Webber grill. They make a stand alone griddle too.
Our Deck just doesn't have room for yet another cooker.
Good news is, Webber now makes griddle inserts. You just take off the grill plates and put on the griddle. You can get a full sized one, or a griddle that will fit in the spot where one grill plate sets. I hope that makes sense.
They are not cheap, but for our family who has a smoker, grill, flowers, and lots of deck furniture, this might be a good option!
There is a guy I follow on Tik Tok (cookingwithdarryl) and I have watched him make all kinds of things on a griddle We love Hibachi Chicken and he has demonstrated making it on his griddle, along with a lot of other things.