So a 40 lbs gnome is not generally as strong as a dragonborn or an orc in One D&D?
As I understand it, some of the racial features are decent enough but those are really the only distinctions between the races and they're all trying to operate within a similar power budget. Thus I would hardly argue that OneD&D is actually increasing racial distinction and uniqueness.
Also, the Dwarf signature role is that of a fighter, but what racial synergy do they have? +1 health and resistance vs poison? Is that even a bigger boon for fighters than it is for squishier classes?
A gnome is not as strong as an orc because the orc has Powerful Build. A gnome would need something like 16-18 STR to match an orc with just 8. That, to me, represents the disparity way better than +2 to STR ever did. The disparity in physical power is much bigger with this setup, and it means even a weak orc is much stronger than a strong gnome.
I personally think Dragonborn should also get Powerful Build since they can get up to 7 feet tall, but I can see why they'd want Dragonborn to focus more on their draconic powers. Their breath weapon is a lot more functional in One DnD, so it catches the feel of being a dragon person a lot better than 5e did. The current version also gives Dragonborn limited flight which is pretty cool.
Also, yah? I'd say Fighters still want as much HP as they can possibly get. Just because casters can also benefit from more HP doesn't mean more HP isn't still a huge boon to melee classes who are in way more danger of getting hit than casters.