Why its broken? USF literally is on pair with any other faction if they invest into either nades or raks, with the total amount of resources spent. Hell, even if they invest into raks+nades, they will be like 15 fuel and 50 MP behind which is less then 15 seconds of income.
The only questionable part is that you have to retreat to the base in order to upgrade your inf, which is not a problem in 1v1\2v2 but its frustrating in 3v3\4v4. Without side grades, USF has second cheapest teching in the game, thats why side grades are mandatory. Getting USF sidegrades arent putting you in any resource disadvantage what so ever, against OKW\Ost.
The only single valid concern about USF is that they have to chose to have either MG or AT gun, both of which are kinda needed sometimes. Other then that airborn is just used for cheesing USF tech tree, abusing idiotic "snipe mechanic" and rushing scotts because of the saved resources, plain and simple. Abusing the fact that faction costs\tech were balanced with side tech in mind, and airborn is allowing you to just ignore it.
And, no offence, but arguments about "rifle performance", sidegrades and why not, which ppl bring here in defence of Airborn meta are utter bullshit.
USF literally has infantry company, which allow you to skip weapon rak in favor of nades\skip, makes rifleman be actually good on open maps and trade well with Axis inf at ranges, allow USF to have mines, allow USF to have proper cover, allow USF to have proper mortar and artillery. Covers almost every single point why usf is on "life support" and the weakest faction.
YET for some reason every one abuses Scottfinder meta, wonder why.
USF was balanced around having smoke on rifleman since Rifles were supposed to be the most versatile mainline in the game. Everything since then has been attempting to bandaid the removal of that along with shitty tech choices.
Mortar is literally a smoke machine, you ask it to bombard a building and there is a good chance that it will miss.
MG was originally designed to be aggressive with fast placement and pick up but bad arc, that was nerfed since it wasn't fair but bad arc was kept.
Pak howi was supposed to be mid/late game bleeder and the aoe was nerfed hard, now you need two and sight for them to pay off which is quite an investment.
Stuart has some of the worst AI performance but it is ok because it has high armor which is high enough against 222/Luchs but useless against snares/Puma/At gun. Its high armor serves no purpose, I would rather have the armor dropped and improve AI performance so that in can actually be used to bleed oponent.
LMG was nerfed to just one since they traded to well, despite the fact that at range most of the Rifleman don't contribute damage. Long range squads literally force Axis out of comfort zone so why wouldn't you pick Paths if they are the only viable option.