I’d say some you just aren’t seeing good Allied play, or the right amount of cooperation between the Allies. If the Allies play as individual countries, then yes they are very beatable, but when they play as one cohesive unit they are much harder to beat.
The UK should have an unsinkable fleet in Sz 8 at the end of Rd 1, US adds ships and buys inf+ships.
Round 2 - Allies (UK/US) land 8 combined units in Alg.
Round 3 - Allies move on Lib and land 8-10 (4 uk, 4-6 us) more units in Alg.
Round 4 - UK can shift to Sz 6, US covers Sz 12 and Afr while maintaining a token threat on Ita.
In this time (rds 1-4) the US can set up it shuck from Wus to Ecan with about 8 inf per territory. This deters the Jap invasions or makes it extremely costly. Why land in Ala or try and kill 8 inf in Wcan when the US can counter with up to 16 inf and probably planes? Can Japan really afford the extra trns and to throw away 8 inf for little gain? Do they have enough already to push through the Chi-Rus stack in Chi or the Rus stack in Novo? What about the Brits in Per? If you go to NA, Japan will be weak in one of these other areas. And ultimately I’ll gladly trade US inf for J inf all game long, I don’t care if it is in Wcan or Per or some other territory.
The UK in the early rds (while landing in Afr) can consolidate its Trj/Per/Ind forces and create a big blocking force that can hold the lines in Per and then retreat to Cauc if needed to help Russia against the Germans. They also can have 1 inf/1 rt from Aus that can land in Afr on rd 3. As for buys I’ll buy all navy rd 1, something like AC, 2 dd, ca, rd 2 buy all air + inf if needed to fill a 2nd trn, rd 3 buy air + inf. Rd 4 you can add in ships when you move back to Sz 6. The air heavy buys are to sink the Ita fleet, hopefully on UK 3 but possibly UK 4.
As for Russia they simply have to hold out against Germany. I buy inf + rt/arm only in the early rds and retreat the eastern inf to the west, as they get back to novo you can decide if you want to shift 1-2 to Chi or if Russia still needs the Inf.
So, the UK lands in Nor in Rd 4. Note, I take Fin and Nor with Russia in Rds 1 and 2. And on UK 5 you start landing 8 inf per turn on Kar. US still covers Afr and threatens Ita, but now with 8 inf per shuck. By Rd 6 the Allies are all over Afr, approaching Trj/Per, and Northern Russia.
Germany better be seriously threatening Cauc by now otherwise they will never be a threat and you can turn all 3 Allies against Japan, just as they start to approach Mos.
Now I’m definitely not saying the Axis can’t win, they obviously can, but just that when the Allies work so well together your window (as the Axis) to make something happen isn’t that big.
Japan as a Monster isn’t that big of deal if Ger/Ita is essentially boxed into the core of Europe by rd 5-6.