There are three main ways of depicting military units is wargames these days: Figures, blocks and counters.
Figures have the advantage of being fun the handle and attractive, but can't convey much game-related information, This means they have to either be supplemented by data cards or limited to game systems that don't get into too much detail. They're also expensive to produce. Counters are the other extreme. They're the cheapest and least attractive (although some games do an awful lot with them) but can be filled with all sorts of game information.
Blocks form a middle ground. They're attractive, can carry a lot of game information and are not as expensive as figures.
They also have a couple of additional advantages. When placed on edge they provide an elegant way to handle reductions in strength and also provide some fog of war.
Columbia's games, for example, make use of all three of the main features of blocks. The games are attractive, always use step reduction and always use fog of war. While wooden blocks have gained some popularity recently, many of the other company's games don't really use all the features.
For example, Simmons Games' titles use the Fog of War and attractiveness of blocks, but not the step reduction feature,using unit substitution instead.
Some of Worthington Games' offerings are Columbia style (like Forged in Glory) but others just use the wood to make sturdier and prettier counters (Like For Honor And Glory).
At GMT, likewise, wooden blocks aren't really used to full effect. In C&C: Ancients they're merely less expensive substitutes for figures, having no FOW or step reduction role at all. But even in Europe Engulfed, their primary role seem to be making the product appear spiffier and providing an easier way to handle step reduction (4 steps per unit) than counters (two-steps) would provide.
It appears that Fog of War is also present, but it seems to me to play a very minor role in the game system, especially compared to the typical Columbia design. Bluff and deception usually plays a vital role in Columbia Games titles, with it mattering a lot what a specific block's identity is.
In EE, in contrast, the key battles usually involve so many pieces that their specific identities and qualities are much less important. There are relatively few regions and important battles will tend to involve dozens of pieces. There are important system advantages for having units at full strength, so it seems there's less scope for deception operations. Is it a realistic tactic to bluff strength by having an area held with a large number of weak units,for example? Or is it an invitation to disaster?