When my child (5) was learning about commercials, I explained that they are a company's way of trying to convince you to buy something. A lot of times they are misleading or don't tell the whole story, so you shouldn't believe what you see in an advertisement.
We have yet to have been hit by a "daddy buy me X" plea based on TV ads. We did get them based on simply seeing things on a shelf in a store, so it's not that the child is immune to this sort of desire.
We have a list that our daughter asks us to put toys she wants on. Then we wait. After a bit we go over the list with her and see if there is still the desire. It has been edifying that most of the time the desire is gone and we remove the item from the list.
I have wanted to do something similar to efficiently dispose of my child's toys. Step 1: I put a red sticker on any toy I don't think has been played with in a while. Step 2: three weeks later, if the sticker is still there then I take the toy and put it in a holding pen. Step 3: if the child has not noticed it was missing three weeks later, the toy can be recycled/donated.
We haven't done this yet, but it's on our list of things to try.
I did something extremely similar with my not-quite-hoarder wife. She had an uncanny ability to ask about a thing the day before it was to make its way out our door. And my “holding pen” was 3 months.
We got into the habit from an early age of just shouting “Cheeky People” over adverts. Until he was about 5 our son would call all adverts the cheeky people, and generally ignore them.
Even now he’s very scathing of adverts on TV, although annoyingly started to get sucked into wanting overpriced cosmetic DLC for games.
You might want to check out games where there are free modding tools and extensive fan-made mods available, like Planet Coaster or Parkitect (both Rollercoaster Tycoon-style theme park building games), Cities: Skylines (a SimCity-type city builder), or the ever-popular Elder Scrolls or Fallout series.
The first three suggestions I would deem kid-compatible (maybe a bit too complex, but that depends on the particular kid), but...Elder Scrolls and Fallout? That stuff's for grown-ups, maybe older teenagers, but definitely not kids of the ages that this thread is about.
The game in question is Minecraft, which in fairness is about as flexible as they get. Sadly it’s also riddled with multiplayer servers taking real money for cosmetic upgrades and super powered pick axes now.
I’m considering moving him off the XBox version and over to a Raspberry Pi or similar soon so he can just play with mods, but that’s a whole other can of worms around properly managing internet access (something he currently does in a very controlled environment).
Immunity was my exact concern as I read about the children being shielded from TV advertising. Yes, it's more tranquil at home, but I have to wonder if to some degree those children are being robbed of a strong modern-day immunity that they'll need later in life?
Perhaps you case illustrates that it's a broad-spectrum immunity that needs to be developed.
We have yet to have been hit by a "daddy buy me X" plea based on TV ads. We did get them based on simply seeing things on a shelf in a store, so it's not that the child is immune to this sort of desire.