So if you actually do the math, and compare AS first-class around the world (for simplicity US to Asia, HKG, to Europe, then back to US):
AA: 110k, 90k, 80k (CX and BA)
AS: 70k each leg.

So, for AA you would need 280k, and AS would be 210k.

Now, neither AA nor AS offer around the world tickets (Oneworld Explorer), so this isn't literally the "RTW" ticket where you can stop a million times as long as you keep going in the same direction.

AS & AA can both sell Oneworld Explorer tickets for cash. [for AS QF will ticket].
But AS - AA do not have a RTW award product. Some other OW ffp's do have multi airline award product with stopovers.
With AS awards the stop over feature, where available, is very useful. AA eliminated stopovers on awards some time ago.

As others have mentioned, the stopovers add significant value. It's a bit of a waste to use an Alaska award. For example, in your RTW example, you can fly F to Tokyo, stop for as long as you want, and then J to BKK (only because there's no F intra-Asia) for a single 75k mile first class JL award. That would require two awards on AA.

This is how I've always used my AS miles in the past. For example, SFO-TYO//TYO-BKK, then BKK-HKG//HKG-SFO, with the TPAC segments in F and intra-asia in J, for two first class awards (145k miles).

You can also use the stopover domestically if you don't want to visit another place. For example, I've done NYC-SFO//SFO-TYO, all in F, with a several-month stopover in SF (I lived there at the time) for 70k miles (the same price as SFO-TYO). So basically I got the return of a NYC trip "for free", booking into F.

I don't know if the stopover thing has changed recently, but sometimes it seems it is not being offered online (married-segment?). If you call in some agents won't do it for you, and some can. So ... (it also seems like Alaska got rid of their partner award desk).

But yes, stopovers are tremendous values. I guess people did the SQ stopover deal initially, though they stopped that.