APS-C isn’t the main problem. Based on the answers, the biggest issues are likely:

• light pollution: dark skies are critical, and city glow can wash out Milky Way detail
• focus: your stars may not be sharply focused
• lens artifacts: some chromatic aberration may be affecting star rendering
• expectations: many dramatic Milky Way images use tracking mounts, stacked exposures, and heavy post-processing

Your settings may also be conservative. ISO 800 can be low for Milky Way work; one answer suggests raising exposure so the histogram is at least closer to the middle, while avoiding blown-out stars.

RAW capture is important, and strong post-processing is normal in astrophotography. If you want results closer to what you see online, the usual next steps are:

1. Shoot from a much darker location
2. Nail focus carefully on stars
3. Continue shooting RAW
4. Be more aggressive in post-processing
5. Try stacking multiple exposures, and eventually a tracking mount if you want the most detailed results

So yes, you can improve this in both capture and post, but dark skies, accurate focus, and stacking/tracking matter more than APS-C alone.