A "remaster" can sound better, worse or the same as an original pressing. There are too many variables in play to give a blanket answer.
Some remasters of vintage/golden age material sound better. Back in the day, engineers had to be mindful of the (low) quality of home listening equipment. Unfortunately this often led to compression and truncated frequency extremes. Example: Verve was forced to reissue many classic titles because 1st pressing were too dynamic for most home systems. Later issues even during the Gold Age sound inferior as a result. It is only with the beginning of true high end remasters starting in the 70's that listeners could hear what was actually on the master tape. RCA Living Stereo LPs from the 50's-60's were engineered to sound great on home equipment- because EQ was applied during the mastering process. The first series of Classic Records RCA reissues cut directly from the master tape with very little EQ or change. Listeners were unhappy because they did not hear "better" versions of what they were intimately familiar with ! What they received was actually closer to the master tape, but we deemed inferior ! Classic incorporated some of the original EQ in subsequent reissues.
Some remasters sound worse. Many MSFL and other premium remasters sound different (and worse to many) because the remastering engineers applied EQ adjustments. Some sound brittle or booming, some have muddled vocals, some sound like a "smiley face".
The best remasters tend to occur when an engineer carefully listens to an original pressing to determine how it was produced, then approaches the master tape from a the perspective of recreating a better version of the original. Example: Beatles in Mono. The engineers and producers used mint first pressings as their reference. Some of the resulting mono LPs sound -better- than original YB Parlophone pressings, and the remainder sound just as good.
We are now at the point where even RnR masters are 45-50yrs old, and suffered from indifferent storage quality, and multiple playback on machines of varying quality such that the tape has noticeably deteriorated. Rather than risk further damage and to reduce costs, labels are transferring master tapes to digital files. Many were converted at 16/44 during the 80's and 90's, then the master tape was discarded because digital is "forever". It is only in the past 10yrs that we see many labels choosing a higher resolution level for digital conversion. Most labels use something between 16/48 and 24/192, with the sweet spot being 24/88 or 24/96. The resulting digital master is then used to create new CDs, streaming content, and to generate mothers for LP pressings. Digital masters are much cheaper to administer- send bits by secure line versus shipping a master tape.... Contrary to industry spin, you CAN hear a difference between a fully analogue LP remastered pressing and an LP pressing with digital somewhere in the production chain. Don't be fooled by claims of "from the master tapes" or anything similar because a DIGITAL conversion is actually taken from the original master tapes as a source !