I believe experts have pointed out the vulnerability is how complex and hence expensive it is to keep these tanks running. It needs a crew of mechanics to regularly service a gas turbine engine which also guzzles jet fuel. They are very heavy which means they can’t be driven on any roads or bridges that are too soft or weak without destroying them.

The tank crew themselves need a lot of skill and teamwork to be effective. They still manually load the main gun. Ukrainian troops would have no training on American tanks. So that time and labour for training up the crew to competency is another cost.

They are less of a resource drain just sitting in storage with the engine off.