I played both RE1 Director's cut and then the remake directly afterwards, this month. I played Jill > Chris in the OG, and then Jill normal mode > Chris hard mode in the remake. Both are great games but I am absolutely baffled by how many people I've heard call the remake the definitive experience that replaces the original.
The OG is so damn funny, it's a completely different experience hearing the voice acting in context instead of just in highlight clips. The remake had more beautiful backgrounds but feels less grounded(who's lighting all of these candles?). The addition of extra content in the Remake is generally good, but at the same time the OG ends up feeling very streamlined which I enjoy equally as much. The crimson heads are cool in concept, but in the end I barely had any meaningful interactions with them. Lisa Trevor is aesthetically a cool addition, but mechanically not scary as she's piss easy to avoid. The OG had more branching paths even if the outcomes only ended in a few ways.
I could go on and on, but yeah, it's strange to read people talk about RE2&3 remakes not replacing the original games, but then just follow it up with the thought that RE1's remake does replace the original. I see this sentiment in a lot of youtube comments, I don't know what the sentiment is elsewhere on the internet but I have no reason to feel it would be different elsewhere.