You're missing the point. If there are more competitions, then it's better for the consumers. Before Sigma Art came along, there weren't any direct competitor for the EF. As for the weight, let's figure that out.
In 2008, the 5D mark II (21mp) was commonly coupled with 80oz of lenses (Canon 20-70mm f/2.8 and 70-200 f/2.8). In 2012, the 5D mark III (30mp) changed the way photogs carry the lenses, shooting primarily with primes, weighing about 35oz (i.e. Canon 35mm f/1.4 and 85mm f/1.8) or 60oz w/ 85mm f/1.4 instead. If we compare apple-to-apple, the sigma art 35mm and 85mm weighs tiny bit more, 0.6oz, than the Canon L.
What you're saying isn't entirely true, quite uneducated guess. Thanks for your comments.
Yes, let's take a look at the lens weight shall we (from TDP). All Ls versus Sigma Sport/Art except for 105mm where Nikon's f/1.4 is used as a comparison.
Lens Canon Sigma
14mm 22.6 (2007) 39.2 (2017)
24mm 24 (2008) 24.5 (2015)
35mm 27.9 (2015) 24.5 (2012)
50mm 22.1 (2006) 30.2 (2014)
85mm 34.2 (2017) 41.8 (2016)
105mm Nikon 36.5 61.8 (2017)
135mm 27.5 (1996) 42.4 (2017)
24-70 29.5 (2012) 37.2 (2017)
70-200 57.9 (2018) 66.9 (2018)
So, let's see... yes, the Sigma's do generally weight significantly more than Canon, especially for lens 2016 and after. Granted the Sigma 14mm has a significantly larger max aperture than the Canon, but I think the trend is pretty clear in Del Paso's favor. So who is cherry picking data now?