Also, no offense, but it sounds like you have a physical limitation that most shooters don't. Positional shooting is physical enough that each competitor needs to understand their strength and mobility limitations and not exceed them; it sounds like you have, but others' limitations are not as restrictive as yours so they're able to carry and move more weight, which has well-understood advantages.
Fwiw, my gun is about 15 lbs and it's fine, balances where I need it to (but just barely). I'm not particularly motivated to get up to 18-20 lbs, but I can absolutely understand why people would; it helps almost every aspect of getting and maintaining stability in the situations common to the current style of barricades. If offhand became popular again people would reevaluate; if people had to ruck their guns half a mile in a stage they'd adjust (and do, in field matches).
Pretty long way of saying: you do you, but you're doing what you're doing because you have to. Others get to take advantage of their lack of strength restrictions, don't be surprised or derisive when they do.
