Agree. There aren't a lot of great options.
At the low end (transaction volume/amounts), you just get murdered on costs. If you've got a niche or high margin business this might be fine.
At the higher end. Well. It seems that a US entity is the way to go. If you structure the vehicle according to some strict rules, you don't incur any US tax. The fixed costs are much, much higher, but the breakpoint is probably lower than people think. This is especially true if you have any kind of cost-base in the US.
There are a few other hacks too. If you're a SaaS business you might consider deeper discounts for annual payment. This is good for cash flow & bumps up your individual transactions. This can change the equation a little - and it's probably better for the $ to be in your customers' pocket rather than a bunch of intermediary financial institutions.
As you say. I'm open to hearing constructive suggestions too! It's frustrating how complex this still is.
Edit: One of the biggest bugbears is AMEX. Even if you get yourself a NAB USD account - AMEX only ever process in the home currency (i.e. AUD). It's easy to be ignorant of this in Australia as AMEX is considered reasonably rare. However, it's pretty much a requirement to operate in the US... So you get this expensive facility, then half your transactions come in AMEX and get processed to AUD anyway (damn). Very open to hear better solutions!