Yes, it is (kinda) explained in later books as well as hinted in the first one.
The first book was released in 2006 and Cixin came up with the idea of the V-suit probably some years before. Remember how technology was in 2006? Or in 2004? The game he created inside the story would be quite amazing even in 2021.
So back then, the V-suit must have cost a lot of money, way outside of the budget of your casual gamer. The main idea of the game was not to find an answer to the three-body problem itself BUT to prepare the players for the world of Trisolaris (as far as we readers know, the Trisolarians didn't want to reveal how they looked even after decades of harmony with Earth fearing that the humankind wasn't ready to see their physical form).
So they were basically recruiting new members to ETO through this game. And since the ideal ETO member would be someone with good resources and intelligence, it would make sense to make the game in such an environment that required so high-tech gear that they could weed out the casual gamers.
We later find out, when the players who "completed" the game meet, that most of them are rich and/or intellectuals. Most of them even comment on how the real world doesn't feel real anymore and they prefer the virtual world.
This implies that it's important to have those high-end haptic suits so that the possible candidates would get stimulated while playing the game.
It's implied multiple times that the reactions and feelings one experiences when in-game can be quite powerful (but harmless) to their real-life bodies. So after every failure or false success they get to experience the effects of the three-body problem not just on their minds but on their bodies as well.