Apple Watch series

From a manufacturing perspective there is very little difference between the Series 4 and 5, so it would have been very easy to switch the Series 4 production equipment over to the Series 5 and be able to crank out millions of Series 5 watches. Vs building new manufacturing for the Series 5, so they could keep the Series 4 in production.

The Series 3 is sufficiently different, from a manufacturing perspective, such that discontinuing its manufacture would not have saved anything switching the line over to Series 5.

The apple watch 4 has been discontinued in order to make way for the watch 5,there is nothing wrong with the 4 my wife has one and says it's the best thing since sliced bread.