True of the main triangle too, which the “more compliant” top tube is part of.
I apologise johnners. I over simplified.
The rear triangle is subject to a point load at one corner, resisted by the other sides.
That’s not at all how the front “triangle” works, which isn’t really a triangle anyway. Indeed the whole frame is actually a truss.
The “compliance” of the main triangle comes about by the fork exerting a bending load about the top of the down tube, which causes the top tube to bend downwards as the wheels splay apart. It’s the wheels splaying apart that gives the feeling of compliance in a bike.
If the front end was triangulated correctly, with a tube going say, from the front hub to the bottom bracket, to “tie in” the front wheel, then it would be a solid triangulated structure. But it wouldn’t go round corners very well.