According to Wikipedia, we have "some 3,700 M1A1, M1A2 SEPv2/v3 in storage". So we have literally thousands of main battle tanks we will never use we could just give them. It's a meat grinder because we're making it so.
What good do MBTs do in isolation against attack helicopters with 15km-range ATGMs?
MBTs do not have sufficient AA or ECM capability ever. Either a specialty formation is required or something carrier sized to have a chance.
Their existence is the old strategy of demolition and suppression of infantry. (At the last of which they do not quite succeed.)