For my wife's 2011 Outback, I recently put in new CV axles (from Subaru), new sway bar bushings (Subaru), new lower control arms (aftermarket, I forget the brand), new sway bar end links (Moog), and new strut assemblies (KYB Strut-Plus). Now the car sits about 2"-3" high in the front. (And before you ask, yes I did properly torque the control arm bushings at ride height). 

What do you think could be causing it? ChatGPT says that the most likely culprit is the strut assemblies, even though these assemblies are made specifically for this vehicle. ChatGPT also says that a lot of people have reported this problem when using the KYB products in Outbacks. Has anybody else heard of this happening? Aren't KYB supposed to be a good product? On the other hand, they were less than $150 no Amazon, and I'm seeing that most of the better strut assemblies are more than $300ea. What other strut assemblies are good, and what would you do in this situation? Do you agree that the KYB strut assemblies that I installed are likely the problem?

Yes KYB are good struts.  Another person posted a like issue a month ago.  

Compare the old to new.  Are they the same with no weight?

If so the spring rate may be different.

If you step on the front bumper, do you get normal compression?

Other difference is aftermarket KYB is a gas strut and OEM genuine units are KYB oil filled. 

Gas filled struts naturally sit higher than oil filled struts. If a gas strut fails it collapses, if an oil filled strut fails it will leak and continue to perform its duties with diminishing performance as it loses oil. 

Cheers 

Bennie