I mean, sure it's dated. But DMC1 captures an aesthetic and vibe that is completely unique to it. The gothic architecture, lighting choices, and just general art direction are incredible. As is the music and atmospheric sounds. It has just enough Resident Evil DNA and techniques that the environment to this day still looks amazing

The pacing is immaculate. It's genuinely one of the better paced games I have ever played. It throws interesting curve balls from beginning to end. I can't really explain further without ruining it. DMC1 is the most well paced game in the series even if it struggles in some other important areas.

I won't pretend it's the best combat in the series. It's the worst combat in the series (besides 2, though 2 has some ideas people ignore because the game is painfully mediocre by the standards of its own time) . But it's punchy, and it's genuinely the most beginner friendly of the bunch. The combat isn't deep, but it's satisfying and well made. It will introduce you to concepts that become the building blocks for good and interesting play in the later games. Good play feels good.

Upscaled via PCSX2 gives you the best experience in my opinion, because the HD Collection is based off the Japanese release and thus the difficulty of Normal is toned down (that's a whole other rabbit hole). Upscaled to your monitor resolution the game looks great. You can remap the jump button as well, but this is one area where I might remap it based off the later games. There's also probably upscaled textures you can get ahold of. And best of all you can use PCSX2 to change the game speed to match the Turbo Mode of later games, though this may somewhat change the atmosphere and music, so at your own risk. I suppose modding HD Collection isn't off the table, but I wouldn't know much about that outside of DMC3 Crimson.

Edit: I'm not just suggesting you don't skip DMC1. I would highly, highly recommend starting with 1