Those are remakes and not remasters. Different beast.
The trouble with remasters is they're usually farmed out to third-party devs who don't always give it the same attention to detail as the original developers. A prime example would be Dark Souls Remastered, which actually makes some of the graphics worse compared to the original PC version.
The line between remaster and remake is a blurry one.
Nier Replicant ver.1.22... isn't officially called either a remake or a remaster, and a convincing case could be made for either. Yet it changes more than Demon's Souls PS5 does.
It is easy to find criticism of Demon's Souls' remaster's art style by entering that term into your favourite search engine. This isn't "considered" true by "almost everybody".
Regardless of any person's opinion on the changes, being substantially different is enough reason that it isn't a suitable substitute for the original.
The trouble with remasters is they're usually farmed out to third-party devs who don't always give it the same attention to detail as the original developers. A prime example would be Dark Souls Remastered, which actually makes some of the graphics worse compared to the original PC version.