It's the same story over and over (Deliverr, Flexport, Amazon, Shopify, etc) 1. the entire ecomm supply chain got way ahead of their skis during the pandemic thinking boom times would never end 2. no matter how good your software is, supply chain is cutthroat — a motivated low-tech salesperson can always undercut you 3. margins are razor thin, so if you're subsidizing prices with VC money to buy growth you can easily…
Nothing else matters beyond that and the price. And it's entirely fungible - nobody cares if it's UPS or FedEx or some random truck that delivers stuff to Walmart or whatever.
The only way they had a chance was getting their APIs so ingrained in companies they couldn't switch, and companies are rightly suspicious of that.