I remember when CD was introduced, Sony/Philips set the fixed output level at 2 volts, whereas at the time the standard fixed output on tape-decks and phono stages etc was, as standard, 1.2v. Many reviewers at the time pointed out that this allowed retailers (remember them?) to demonstrate (remember those?) the "superior sound" by simply switching between sources. Of course the CD sounded better, it was much louder. The increase in volume was, of course, a marketing ploy. The 2v output did allow the use of a passive pre-amp as the signal level could be attenuated rather than boosted by an active pre .I don't use a streamer so I can't comment on the output of such devices, but all the digital sources I do use have variable outputs which I can set so that the speaker level stays the same regardless of source. I know that some people use in-line attenuators to match source output levels.
As far as "remasters" are concerned, they aren't always better than the original, I read, sometime ago that an album by a famous rock group had been remastered, the engineers responsible bragged that they had managed (with considerable effort over several days) to remix it with the drum kit more forward in the mix, but that it was worth it to get an album of tracks more representative of the bands original intention. Hurrahs all round!!! Better sounding and more like the band had wanted.
In the next paragraph a member of the group (still extant after all those years) indignantly pointed out that when they were mixing the original release they had spent several days working to get the drums to the back of the mix as they sure as hell didn't want them at the front!!! he continued by advising fans not to buy the album as it was rubbish!
Needless to say the engineers remixing the album had never thought to involve the group.