The tech companies are not analyzing things at this level. They close a number of accounts each month. A certain number of those were engaged in fraud and will generate chargeback activity. Others were legit but accepting payments in advance. Once the business is out of business those too will generate chargeback activity. Some are legit but had bad service, lost key employees resulting in complaints. Once the account is shut those also often generate chargebacks.

So they sit on the money for 180 days, it doesn't cost them anything and saves them a big pain in trying to claw money back from any of these folks who may not look at them that fondly after being cutoff for what may have a been a silly reason.