It is not necessary to throw away the lens, as zoom creep on this lens is trivial to be fixed (or some could say worked around).

There is a gap between rotating parts, between the distance scale and the zoom ring of the lens. Purchase a 20 USD collection of O-rings of variable sizes, and put an O-ring over this gap. The O-ring I used is marked F-32 and it appears to have an inner diameter of two inches and tube diameter of 3 mm so it's relatively thick. It requires a bit of force to put the small O-ring around the large lens (diameter 79mm at this location), but once this has been done, the O-ring resists rotation of the lens so much that the zoom creep no longer occurs. The zoom ring is markedly stiffer to turn as well after this modification, much to the horror of Ken Rockwell. Problem solved!

Depending on the severity of the zoom creep, it may be necessary in extreme cases to use an even smaller inner diameter O-ring. Furthermore, the tube diameter of the O-ring probably affects what is the optimal inner diameter of the O-ring (thicker-tubed O-rings require less difference between the O-ring inner diameter and the lens outer diameter), so don't treat "2 inches" as an absolute truth.

The modification likely improves the weather resistance of the lens, as well. It is practically invisible from a distance: as the O-ring is black and small, nobody notices you purchased poor-quality gear and had to modify it. For someone to notice the modification, one needs to look at the lens very closely.

Others who have solved the zoom creep:

• Rubber band, not o-ring, in another location: https://www.youtube.com/watch?v=UQb5GIwYgdw
• DIY rubber band zoom lock: https://www.youtube.com/watch?v=Q3Za0DuX9EY
• A differently sized O ring in last answer of first page (tube diameter 0.6mm x inner diameter 30mm so there's more stretch in this): https://www.dpreview.com/forums/thread/2845637
• A proper fix: https://www.reddit.com/r/photography/comments/204tr2/how_to_fix_canon_24105l_zoom_creep/