I watched this Concord trailer and I think I see some of the issues

https://yewtu.be/watch?v=7jqQJhjf_3o

One is that hero shooters have traditionally been sold based on the characters (see Team Fortress 2 Meet the Mercs as well as the initial Overwatch ads). This allows the players to develop an emotional connection that pulls them deeper into the game. It introduces the game-world from a specific perspective, rather than just dropping lots of content on the player and hoping they piece it all together.

This trailer looks like they're selling it based on the mechanics. While they do introduce various characters I didn't feel like I got to know any of them or see why I should care about them. Instead, we get "here's this character, and here's a couple cool things they do in-game". I think prior character shooters have done a better job of connecting the character visuals to their in-game role. A good example (from a totally different genre) is Plants vs Zombies, where the plants are rooted in the ground because they're plants (and also because that's how Tower Defense games work). The zombies are a horde of slow-moving adversaries because they're zombies (and also that's how Tower Defense games work). In Concord, the big tanky guy is a tank (kind of) but it seems to end there. The other characters (to me) don't really communicate what they're about.

The girl-boss voiceover is also off-putting. There's a bit of tone confusion - are we mercenaries out to survive by any means in an unforgiving galaxy, or are we on some sort of crusade for good?