First of all the US early game is fine. There are problems vs OKW on maps with strong cut offs but thats more of a map than a faction issues. USF isn't strong in teamgames but that's not an early game issue. It's important to remember that you need to play completely different styles against wehr and OKW. (roughly speaking spread against wehr, keep stuff together vs OKW)
Secondly, people need to let go of the "I want my faction to be less of a inconvcenience to play" mentality. There are still quite a lot of important decisions left to make in USF tech and thats a good thing. I want to be forced to make decisions with consequences. I don't want to get upgrades without additional fuel costs so they become a no brainer. I don't want to have access to every unit in the tech tree every game without any disadvantage.
The most important tech decision is LT vs Cpt. You can change the balance of those two to make the decision more interesting but do NOT simply remove it by making tech linear.
When do I tech grenades ? Another interesting decision to make. It's totally vaild to go quick grenades before teching. Why remove that possibility ?
Similar story with weapon rack upgrade. Do I want to delay my light vehicle to get an infantry firepower boost ?
I dont want to play this game on autopilot mode. Leave US tech as it is.
My issue is more that you have all these team weapons and elite infantry (and two doctrines that are supposed to be focused on utilizing said elite inf, being airborne and recon support) but they kind of feel sidelined or less accessible because you have to have a bunch of riflemen in the early game but then are given another free squad and then have to go pay a ton to properly utilize them (healing, nades, and racks). By themselves, none of these would be problems but put them all together and you're more or less forced to mainly rely on a ton of infantry with very few other units in the early/midgame, which IMO is poor design. It's not gamebreaking but I wish I could actually utilize all these things instead of just having more garands.
All the other factions in the game have other alternatives that are much more accessible and therefore feel much more flexible as a whole IMO.
Soviets have 2 tiers each with non-infantry alternatives (snipers, scout cars, team weapons).
Brits have a varied T0 and a fast tech to t1.
Ost have a varied t0/t1 with a bunch of team weapons and a sniper.
OKW at least has some infantry variety and the kubelwagen.
I'm fine with having to make choices like "which tier do I go for?" (i.e. okw t1 or t2 or soviets t1 or t2) or "when do I get this sidetech?" (soviets and brits) and in principle I'm fine with the way you have to choose tiers and sidetech with USF as well but I feel like in practice the above combination of things I stated in my first paragraph really hampers them. It also doesn't help that the two tiers are somewhat flawed (captain having no suppression and lt having all of it, lt having no reliable at and captain having all of it).
I say this with a grain of salt as I just played a 1v1 where none of my infantry got wiped and I still managed to get a pack howie, an at gun, and rangers XD, however that's mostly because I was bleeding him a lot more than he was bleeding me.
And that being said, I do see where you're coming from, I just happen to have a different opinion.