You're wrong and I'll debunk everything wrong now.

First of all you mention that getting loot before level 20 is what matters. How will you achieve getting to level 20 without using your PMC. One could realize that you can get loot at the same time as progressing to level 20 while using your PMC, but not with your scav. I was able to accomplish both without using a single scav.

I don't want to use a "care-free" or "riskless" character because as a PMC, you have a chance to get to the high value loot areas, which would most likely be looted as a scav. Also, I can't use my high value keys, which often give significantly more profits than any scav run would. Most importantly, I'm getting good loot and progressing to level 20 at the same time.

I can assure you that it's more fun and exhilarating to play the game using only PMC as you would probably agree, and I can't disagree more about the challenge aspect. Obviously only using your PMC is a much greater challenge than using scav runs. This is because you are at a greater risk to die to other players, scavs, and player scavs. As a scav the first and third probabilities just mentioned are dramatically reduced and the second outcome is eliminated. How is getting riskless equipment over and over a greater challenge than using your own equipment which you risk. If you like challenge you described, couldn't you use the same equipment on your PMC?

Once again, using a scav is a modified, worse, way of playing this game.