Agreeing with Snakes and Ladders, Uno, Connect 4, Frustration, and Pop Up Pirate.
DS loved the Orchard game 'Catch and Count' at that age.
Junior Monopoly and Junior Game of Life are good for this age. You just help them read the cards.
A firm favourite in our house is Tyrannosaurus Rex. It says 6+, but it's not complicated so would be fine. It's a similar concept to Frustration.
Tyrannosaurus Rex Board Game amzn.eu/d/90xQGUr
We also have a couple of Top Trumps/Match the Crazy Cube games. You can get then with all different characters. Just linking the cheapest one I found. Loads on Amazon though, depending on your DCs interests.
Top Trumps Disney Pixar Lightyear Match Board Game, Play with Izzy, Mo, Zurg, Sox the Cat and Buzz himself, Educational strategy game for ages 4 and up https://amzn.eu/d/0EGB5dd