That’s not exactly a fair comparison since Pokemon is more of a multimedia franchise in that it has trading cards, tv shows, movies etc. It’s more like a brand than just a video game. So barring these huge franchises (along with Minecraft/Fortnite), I would assume physical merch sales for most games is low by comparison.
I think Pokemon is a brand because they started with the video game and capitalized on its merchandisable nature. I don't think there was was a Pokemon card game (or anything else) until after the video game was released.
I agree some games are less amenable to the merch model, but that is within the control of the game designers.
In fact, some games were designed explicitly to support the sale of merchandise. I think Rovio's Angry Birds and/or Seriously's Best Fiends used this strategy, but I can't find the source, now...
Yes, the original Gameboy game was first. The other branches followed quite quickly though, so they probably fed into each others popularity and I'm not sure it would have made a huge difference if e.g. the anime had come first and a bit later then the games. EDIT: that all these channels were there was probably quite important though.
detaro makes some good points, and you’re right it’s totally possible for some things to be designed for selling merch. I agree that it’s really up to the game makers.
At this point, I think it’s more about IP and who your target is. If your target is general audience/kids, you could probably sell a whole variety of merch, even if it’s not directly tied to the game.
But if the target is hardcore gamers (collectibles, exclusive t-shirts, memorabilia, etc), the market seems smaller.
Pokemon's merch revenue completely dwarfs game revenue: https://youtube.com/clip/UgxvU_ygdejMiTGyChN4AaABCQ
Merch is great because it allows "whales" to spend as much as they want without the questionable gambling aspect of loot boxes/gacha.