It is far from useless, it’s just not as vital as some others, nor does it provide a linear benefit akin to melee or ranged skill – it really depends on the equipment and role of a character. While lightly-armored characters can consistently go first with some investment frontliners with heavy gear will benefit less, and – more importantly – they have higher priorities.
the initiative figure have a very little chance to change the tide of battle
Me and my archers/crossbowmen respectfully disagree. Being able to quickly snipe key targets (enemy crossbowmen, necromancers, shamans) before they can act can dictate the flow from turn one. As can breaking enemy’s morale even before they reach melee. Are they already in melee? Even if you can’t kill them outright it’s sure nice to stun or injure a heavy-hitter before he gets a swing at your bros.
Speaking of morale, if some of your brothers get routed you better hope that your captain can act first and rally them before they get themselves chopped.
I could go on, but I think I’ve made my point.
If you’d like a good turn-based tactical combat where you can overwhelm your enemies with speed matrix-style I recommend Fallout 1 & 2, it’s quite easy to pull there.