The aircraft you found was created in 2000 [0]. The 757-200 does date back to 1983, but definitely not this one. The owning company (DHL Air) was founded in 1989, perhaps this was the date you found?
Your random choice also did hit an interesting quirk in aviation that cargo airlines tend to use old aircraft that are no longer fit for passenger operations.
There are several reasons for this, but cargo ops are able to use their aircraft in ways that maximise their life [1]. Passenger airlines try and maximise the time each aircraft is airborne (i.e. earning revenue) whereas cargo operators often schedule differently. This sometimes allows for operation of aircraft that have very few pressurisation cycles left in their lifespan.
The specific aircraft you found was retired from passenger ops in 2016 (after being in storage since 2015) from Icelandair when DHL purchased it [2]. This is when the airframe was 16 years old. It was converted to a freighter variant at this time - the 757-256.
You can look at fleet ages to get an impression for the age of aircraft, and generally passenger airlines (especially in developed countries) are using newer planes and cargo airlines have a much older fleet. You might have noticed this when you see old fashioned designs like tri-jets, or four engined jets like the 747 only in cargo livery at airports.
Your random choice also did hit an interesting quirk in aviation that cargo airlines tend to use old aircraft that are no longer fit for passenger operations.
There are several reasons for this, but cargo ops are able to use their aircraft in ways that maximise their life [1]. Passenger airlines try and maximise the time each aircraft is airborne (i.e. earning revenue) whereas cargo operators often schedule differently. This sometimes allows for operation of aircraft that have very few pressurisation cycles left in their lifespan.
The specific aircraft you found was retired from passenger ops in 2016 (after being in storage since 2015) from Icelandair when DHL purchased it [2]. This is when the airframe was 16 years old. It was converted to a freighter variant at this time - the 757-256.
You can look at fleet ages to get an impression for the age of aircraft, and generally passenger airlines (especially in developed countries) are using newer planes and cargo airlines have a much older fleet. You might have noticed this when you see old fashioned designs like tri-jets, or four engined jets like the 747 only in cargo livery at airports.
[0] https://www.planespotters.net/airframe/boeing-757-200-g-dhkc...
[1] https://simpleflying.com/cargo-operators-older-planes/
[2] https://www.airfleets.net/ficheapp/plane-b757-30052.htm