Boxes marketed as 'Streamers' are like boxes ISPs give you called 'Routers'. They amalgamate a number of functions in one box in the interests of convenience. A DAC and digital media reader in the case of the former and a modem, router and switch in the case of the latter. You could get separate boxes to do each of these functions, but it's not always worth it.
....except for the function of reading digital audio media. Linn and others charge a fortune for something that really only differs from a pi in terms of firmware and ui. The output is identical. Would you spend £1500 extra on a washing machine just because it had a touchscreen? In effect that is exactly what many hi fi manufacturers are suggesting you do and they deserve your contempt and, possibly, pity.
Buy a fancy pants streamer by all means, but you are being ripped off. I'm still out on DACs. I've tried a bunch of competent DACs over the years retailing from £100 to £1000 and the differences are marginal. I suspect a very old audio alchemy dde 1.1 that only handled up to 48/16 is still the most pleasing dac I've used to my ear, but it's marginal.