Shimano 105 5700 in 2019

I want to begin with road biking as a sport and are currently trying to find a decent bike.

Some friends recommended to get the Radon R1 2019 with a complete Shimano 105 R7000 groupset.

In a bike-store I found a new no brand bike with a complete Shimano 105 5700 groupset.
It also features an aluminum frame, a carbon fork and weighs about 10.5kg for less than 300€.
Is it still relevant in 2019, as it is almost 10 years old, or is it comparable with newer Shimano Sora groupsets via trickle-down?

There seems to be a lot of myths and opinions on various groupsets, but is there some “evidence”, which indicates a different performance?