I don't believe that as a general rule it is possible to conclude as a general rule that digital masters are better or worse than vinyl masters. In my opinion, well mastered recordings sound great, digital or vinyl, and the reverse. As a case in point, the Tom Petty Album "Mudcrutch" was released on both vinyl and CD, but the vinyl copy came with a CD derived from the vinyl master (it was never sold separately). The CD that came with the record was intentionally higher quality as compared with the commercial CD, which was compressed and loud. Putting it another way, The CD that came with the LP sounded like the LP (without the disadvantages of vinyl). The NY Times published an article on this release, the mastering, and the general topic of mastering CDs that is worth reading:
https://www.nytimes.com/2008/06/23/business/media/23petty.html?searchResultPosition=2 For anyone interested in Tom Petty, the follow up mini live album also came with a CD mastered to the standards of the LP.
I have read that that mastering quality varies with the streaming services, but that the streaming services' audio quality is somewhat compromised by compression or limiting compared with high quality download services (hdTracks etc.), although I have purchased supposed "hi-res" download versions that were horribly compressed and loud, so I don't actually trust any format if I don't know who did the mastering.