why are all Amazon Prime drivers either Hispanic or black?

Yet they receive less promotions than whites, get fired at a higher rate. 

ALL of them are?  Where do you live?  In the Rio Grande Valley in Texas?

Structural racism probably, but I've seen loads of white drivers.

Because they work for UPS and FedEx. 

a BUBBLE  BOY world  question ...the  BLACK SWANS  FALLACY  is the tendency  of people to ignore  evidence  that contradicts their BELIEFS and ASSUMPTIONS  a tendency to BELIEVE that things they never WITNESSED don't exist .a form of confirmation BIAS

the classic deduction went like this

1- ALL Swans are white

2- the bird is a swan

3- The Bird is white

  but in  1697  Wilem de Vlamingh a dutch explorer discovered a black swan while on a rescue mission in Australia

DATA  is AMAZON PRIME   most  drivers  are in the 40 + age group ( 61 % )  more are MEN( 55.4%) than women ( 44.6 % )  Most are Married most are parents most have a education AMAZON prime is a GLOBAL COMPANY of all ethnicity  and nationalities

  in the USA  race and Ethnicity  data SHOWS

Asian 13.6 % Black  26.5 %

  Hispanic 22.8 %  Native American 1.5 %

  two or more races 3.6 % White 32.1 %

the USA population is

60.3% non Hispanic white 

18.5 %  Hispanic or Latino

13.4 %  Black  / African American

5.9 % Asian  2.8 % two races or more

1.3 %  native American   Alaska  native

0.3  Native Hawaiians or pacific islander

Bwcause tjey are deiven for success. I can't imagine there being no Asian drivers

Same reason Why all school shooters are white 

That'll change when autonomous vehicles become the norm.

Most of their drivers are young.  Asians are a small minority overall and whites are a small minority among young people. 

their business not yours..