And of course, despite it being "the most ridiculous thing said on FT today" all of the options on your screen have Y space on each segment but it is being suppressed by married segment control (presumably to get much higher-yield nonstop Y fares). The one they deign to sell in Y has at least M space on every segment.

But indeed leaving LAS seems to be the bottleneck:



ed. to add, also ITA is in general much better about finding solutions with fare breaks: