If there's any truth to what you say, then each of these immigrant workers receive a salary which is significantly higher than their US born colleagues. They are as you say "top talent from around the world". A person who is among the world's best certainly has at least double the salary, right?
Many do. Look at the ranks of founders, context level execs, all made up of a disproportionate share of immigrants. That's also not necessary to justify the proposition that immigration doesn't reduce market wages if it increases demand. It is possible that the demand for software far exceeds software developers and we could 10x or 100x employment and demand would still keep wages the same. You need to show why the fact of salary levels and directional trends are causally linked.