You're not going to be more accurate by laying in a waypoint over a moving map. Get the correct lat/long for the waypoint, and you're dead-nuts accurate.
Scroll a cursor around and drop it where you *think* the waypoint is, and you're not nearly as accurate.
The waypoint is just a blob on the magenta line. For
en route navigation it doesn't matter a toss if it is a millimetre or two away from a theoretical position which might (entirely arbitrarily) have been picked with lat/long co-ordinates, and it certainly does not need to be "dead nuts" accurate . Indeed earlier in the thread you were extolling the virtues of not flying directly via a waypoint. I submit it is far safer to use the cursor for enroute waypoint selection, although I endorse Pace's assertion that the art of lat/long should not be forgotten.