With almost every consumer product today. Cars are a great example at thousands more that can and do fail yet you paid or are paying continuously even if it's in the shop.
I can't answer why you didn't get your new laptop as I am not a Dell employee or rep but one time here in these very forums a complaint was made about a tardy delivery and the member did not think the flooding over the entire state of Nebraska which shut down all the interstates should have delayed his shipment (in Nebraska.)
This laptop arrived and did not function. A Dell engineer visited and replaced the faulty component. The next day the same fault occurred. Dell's Technical Dept. confirmed a new laptop would be dispatched. The terms and conditions imply - if an exact replacement is not available the next model up will be supplied. An order number for a replacement laptop was given and consistent assurances were given for delivery to be made within 3 days. This has not happened. I have now waited 4 weeks for a replacement. This has impacted on the efficiency of our business. Technical support have now assured us a refund will be made. This refund will take 4 days of more!!!! An e-mail was requested to confirm this, it has not arrived. I have been a Dell customer since 1988. I do not expect Dell to keep my money for 4 weeks and not deliver a functionary product. I have heard so many times the laptop will be with me in 3 days, I do not have faith in Dell. Please confirm I will receive a refund without further delay! Regards May2019