Well executed SMPS is way better that linear power supply IMHO. They only got bad rap from very poor noisy computer implementations.
Linear power supply with huge transformer and a lot of capacitors is in reality a primitive SMPS operating at 120Hz drawing current from mains in short pulses of high amplitude, switching at maximum voltage. It produces not only 120Hz ripple (hard to filter out), but also high frequency switching noise, not to mention that is line and load unregulated and sensitive to DC presence in supply. In contrast, resonant mode SMPS is very quiet switching at zero voltage / zero current. Transformer can be very small because of high switching frequency that is also easy to filter out without huge capacitors. In addition it is line and load regulated and insensitive to DC on mains (can operate from DC). Benchmark Media reduced noise in DAC2 by 10dB replacing linear supply with SMPS. They use SMPS in AHB2 power amp achieving 132dB S/N. Other companies, like Rowland, eliminated linear power supplies completely. So, with all these benefits of well executed SMPS, why do we still produce these monstrous unregulated linear supplies? Perhaps it is because designing resonant mode SMPS is not so easy, while Linear Supply has only 3 components? Perhaps market demands it (People still strongly believe in them. Big and heavy must be good)?
I'm also not sure what "Off-the-shelf" ESS board is.
In general, if somebody is taking advantage by selling gear consisting of some kind of generic modules people are free not to buy. If these modules are so generic it would be easy to buy them and to build DAC or amp.
Are we offended by fake or inflated advertising? Not in audio, for sure.