The economics of scale trickle down into cost savings for the consumer, even if it is by only a fraction of what the manufacturer saves. There's a reason the id.4 costs about the same as a base Model 3 and you get less of a car for it (not factoring in federal tax credit, which might be returning to Tesla soon anyways).

The manufacturers no doubt. Musk, and by extension Tesla, has been seriously focused on ease of manufacturing. Probably since the huge problems Tesla faced in the late 2010s.

They should be. The longer the build cycle the more errors there will be in the build.

Each job is a dependency for the next job. A long build time either indicates that individual assembly technicians have too many steps in their job (it is much harder to remember 25 steps than 5 steps) or that the plant is assembling more parts locally than their competitors. If you have an engine shipped in complete from your supplier that is less time your plant spends assembling a dependency at build time.

Electric cars should in theory assemble much faster than gas. Fewer parts. Less complexity in the mechanical assembly of the drive train.

When corporate overlords dictate that an assembly plant meet production numbers that it isn’t capable of accurately producing they shell out complete garbage. Inspection lines flag errors that managers ship with disregard in order to meet numbers. Every time.