Why still use rivets? They don't mention spot welding.

View: https://www.youtube.com/watch?v=EHAKlE6XzWs

Spot welding makes it harder to remove a panel for repair.

If you don't get the welds right you can lose skin panels (or even the whole aircraft).

This is misleading; many aircraft use spot-welds. The key is to using them in the correct place. For example the C-130 falsework panels (wing trailing edge) are comprised of inner strengtheners and outer fairing panel which are spot-welded together. Ditto for many of the other removable panels on the aircraft (engine cowlings for example).

Nowadays similar methods of construction still exist, but with spot-welding replaced by bonding.

Ease of manufacture and repair are big selling points for rivets.

Imagine using a spot welding mechanism to build the aircraft structure (including the skinning) in the cover image of the video above. The spot welding electrodes would have to be able to reach approximately the same locations as the rivets, while moving around and through other bits and pieces of the internal structure, and possibly around and through equipment depending on what stage of the initial assembly process you are at. The initial assembly process might be able to incorporate such a method, but imagine trying to design a machine that could do such a thing on an aircraft the size and complexity of a 747. In addition, imagine trying to do the same thing - possibly in the field or at a smaller airport, or perhaps in the field at squadron level for military aircraft - when trying to repair damage.

Also, when a properly designed riveted structure begins to fail it is usually significantly easier to detect, using less sophisticated equipment, and subsequently more reparable than when a spot-welded structure fails. This is mostly due to the modes of failure for the different fastening methods - which unfortunately is a subject too complex (I think) to cover in detail here.

If you are interested, do a search for 'rivet failure mode in sheet metal' and/or 'spot-weld failure in sheet metal' (or similar word strings) for a fair number of papers and articles written about, and with descriptions of, the types of failure.