Something that always seems to get lost in streamer discussions is the idea that all streamers are computers. The dedicated streamers use computer motherboards, in some cases the exact motherboards you may find in a standard computer. SOTM makes the only dedicated audiophile motherboard I'm aware of. Then we come to the hardware used with these motherboards, processors, RAM, SSD, etc. I see nothing special being used with most dedicated streamers, most use standard stuff one finds in general service computers. As far as processors most use rather low end so as to keep noise down, more easily accomplished vs more powerful processors. Less powerful processors don't allow much if any dsp, manipulating digital bits via dsp may result in much higher sound quality. As far as the rest of the hardware, one can do much better than the common parts found in vast majority of dedicated streamers, enterprise level hardware with extremely low levels of latency contribute to lower levels of jitter vs the dedicated streamers.
Dedicated streamers do come with optimized operating systems, which can be replicated by the diy. Issue is diy needs to acquire the knowledge in order to maximize OS. Some dedicated streamers also have proprietary music players which may or not be superior to the Roons, Audirvanas of the world. Both proprietary OS and music players are also available to the diy, so this need not be a consideration for direction taken.
Then we come to power supplies, the better dedicated streamers do come with linear power supplies, again something available to the diy.
End result is I'd put my custom build streamer up against any off the shelf dedicated streamers out there with exception of Wadax and Taiko Extreme. All enterprise level parts, JCAT PCIe board, proprietary OS, proprietary music player available along with Roon, HQPlayer. Finally, I'd put my LPS up against any lps available at any price, over thirty years in developing this lps, first totally linear power supply ever developed for Windows based motherboards.
The point of this is don't fool yourself that dedicated off the shelf streamers are the end all of streamers. The diy or custom builds can equal or surpass sound quality of off the shelf.
But going back to OP. Yes, one does need dedicated streamer, whether diy/custom build or off the shelf. My first foray into streaming was with general service computer, my first custom mac mini way back in day easily surpassed the general service. The general service computer is noisy environment, noise takes away from resolution, resolution you can never get back once lost. Optical solutions may block noise from dac, but can't give back what's lost in streamer. General service computer does not belong in audiophile streaming setup, one has handicapped their system at the source. I don't know why this question is continually asked with so many here attesting to the value of dedicated streamers. Yet to hear a single instance of someone contending general service superior to dedicated streamer, speaks volumes.
