No, German half-tracks were not a waste .... if you consider how many infantry casualties they prevented ... while Germany was running low on man power.
Kangaroos were a field-expedient solution to the massive infantry casualties suffered by the Canadian Army in Normandy during the summer of 1944. By early September, the Canadian Army stalled after liberating Antwerp because they ran out of replacement foot soldiers. The Black Watch suffered 350 percent casualties.
Massive casualties sparked a Conscription Crisis back home, but the war ended before enough new recruits reached the front.
Meanwhile a field workshop (coded Kangaroo) swiftly converted hundreds of M7 Priest SP guns and Ram Tanks. The M7 Priests were idle because their 105 mm gun tubes wore out. Priests were converted by welding salvaged armour-plate over the gun slot and extending side armour upwards. Some accounts say that Priest Kangaroos could carry to 20 men at a time ????
Meanwhile a stack of Ram tanks are stripped of turrets and repurposed as APCs and ammo carriers (Wallaby).
Post-WW2 the Canadian Army kept Kangaroos in service until they were replaced by (purpose-built) M-113 APCs circa 1960. During the 1950s, the Canadian Army even Kangarooed a batch of M4A3E8 Sherman's that they bought post WW2.
Returning to OP trucks, half-tracks, etc. reduce infantry fatigue during approach marches. Once near the front line, even lightly-armoured APCs reduce casualties from shell fragments.