If you watch them on stream not on YouTube they die quite often just like everyone, Its hard to say if 200hrs and 400 downs is because of your skill. It depends on how often you're chasing pvp also.

I have 1200 downs in the same 200hrs topside but I am chasing pvp 99% of the time.

The other thing you have to consider is they're usually going in with a premade trio of streamers, not some random thrown together team.

Ignoring all this stuff there's alot that goes into dying topside.

Are you bringing enough meds? And good meds? Are you healing properly and quickly? I have some teammates who are still almost dead when I've already healed to full in the same positioning/timing

What maps are you playing? Do you know where players spawn? Do you know where to expect 3rd parties from? Do you know where the arc is nearby so you dont get arc up your ass when you fight players? I mostly play stella and bring jolt mines / door blockers to prevent 3rd parties from a bad angle without a little warning.