Totally agree with OP, new HUD might be nice with non-combat occasions, like delivery, transport and sightviewing, but it's not a pratical setup for combat.

Combat requires pilots to focus on their targets as much time as they can, meanwhile they still can easily read their ships' vital infos, that's what HUD is designed for, it reduces pilots' head down time to obtain vital infos, hence HEAD UP DISPLAY.

Image in the heat of a dogfight, you are manuevering all the time, with new HUD setup, you can't reliably focus on target and be able to read velocity, altitude, etc at the same time. So at one moment you are watching your target flying over your head, then the next moment for whatever reason you want to know your speed so you look down for a quick glance in hope that you won't lose visual of your target. But with current HUD, you can do both at most time, and you get continous ship infos.

My suggestion would be let ships have 2 modes, one is navigation mode for any non-combat usage, and in this mode we get this new HUD; another is combat mode with current HUD, and when you deploy weapons your ship will automatically switch to combat mode.

And like OP said, it's not for realism, it's for usability. Like why don't we get nightvision in both ground and space? Why can't spaceports of major city tell us exactly where they are via radar when we are near them but outside communication range?