SD cards on Androids are kind of weird. It's not always consistent where things will be stored. Unless things have changed, many apps can't be installed to SD (and if you force it, you'll find that they are subtly broken). When you're building the phone to hit a low price point, you might not have the budget for a slot anyway; and unfortunately, you're likely to not put much more storage than is needed to boot the phone; let alone handle the play store updates that will be ready when it's unboxed.
It would really help if Google made translations suck less. They are stored uncompressed in the apk, even though human language text is easily compressed.
Back in the early Android days, this wasn't the case, you could easily push most apps onto MicroSD. Yet, versions of Android up until adoptable storage was added (which essentially makes your mSD non-removable) have continued to make it more and more difficult to use your MicroSD for storing apps.
It would really help if Google made translations suck less. They are stored uncompressed in the apk, even though human language text is easily compressed.