i agree with the part that seed plants are stronger and yields a little more, they also need to be veg a little longer for maturity before flower than clones.
Now genetic drift its not nearly as severe as stated and much more complex. Tissue Culture will bring back original vigor tho.
You may have genetic drift over many many generations of clones, hundreds maybe, probably much sooner if the cloned plant contracted some kind of virus, disease, or are in decline of vigor after poor cloning practice, poor maintained moms etc etc etc, theres A LOT of variables that could lead to genetic drifts.
But it isn't "30-27-22-18 THC" drop with each generation,
terpenes could go a bit higher or lower as do the THC after generations, also vigor could start to decline because of bad cloning practices/other factors and also probly mainly because of environment factors/grower mojo, we have clones of the original 24k cut from DNA around, and they are pretty much the same after more than 10 years its being brought overseas, potency and
terpenes, this clone have being copied madly and never was tissue culture "reseted" during all this years.