You are correct that lifts that result in steeper A-arm and steering angles put different/higher loads on the idler arm and its bushings. The load becomes more of an up and down movement instead of just pushing back and forth pivoting it. This makes it easier to bend the arm and wears out the bushings faster. However, changing only the steering to correct this would create bump-steer and handling problems.

The tie rods must swing in the same arc as the A-arms, otherwise suspension movement will induce bump-steer (tire will turn as the suspension cycles). Most lift kits keep these angles the same in relation to each other.

This is the good thing about bracket lift kits- they pretty much keep A-arm, CV and steering angles stock and only the drive shaft angle changes.

T-bar and spacer lifts do the opposite- the drive shaft angle stays put but steering, A-arm and CV angles get steeper.