You may want to pick different brands to illustrate your point as Toyota and Nissan make objectively better cars than the "premium" brands. Statistics show Toyota and Nissan are much more reliable than the German brands. That in turn does illustrate the point people are making. Would you rather drive a basic and used 20 year old four cilinder BMW 1 series or a brand new 8 cilinder Toyota with all the bells and whistles for less money? I like good quality kit as much as the next guy but this is essentially a basic signal generator sold at a huge premium due to the badge. By omitting basic features it's not even that good a generator, regardless of any real or supposed quality difference.
I was rather about comparing Rigol's DG2000 series vs Keysight 33500B series.
The DG2000s have specifications that basically meet those of the 33500Bs, but at basically half the price.
There are some details that makes 33500Bs (and 33210A) better for some use, for example at low frequency, sine wave is only 0.04% THD vs 0.075% for Rigol.
For audio, the 33210A would be perfect.
Comparing BMW with Toyota or even Nissan, is indeed incorrect as Toyota has a long proven history of reliability, and objectively, you can indeed consider them "better" than other "premium" brands.
In particular, total cost of ownership is no match: cheap at buying, cheap at maintenance (parts easy to find, no loss of resale value by not going to manufacturer's licensed garage, no need for "premium" gas), proven reliability, etc.
However buying cars, is not something so "rational" for some people, hence Mercedes, BMW can prosper.
For engineering, even if Keysight is more expensive, for "professional" use, there are still a few reason to pay the extra price.
In particular, this is a "proven" company, it has a network of distributors.