The death of fun in GAC & TW

Are you sure it is mainly because of DC? I mean I don't like DC as well. And I can understand the new fun you discover with a fresh alt (happy for you). That's why many seasoned players start alts, because you are (again) limited in your options and have to force yourself into investment decisions, which you probably long forgot to be necessary. All of that brings back fun. Absence of DC? Yes, maybe a little as well, but don't think it's decisive.

On to the grand schema: DC was actually a bit of fun when they got introduced because it disrupts the norm. But now, it's part of the routine in top-end GAC. Apart from the short period when a new set is introduced and everyone is running around trying to figure what's the best combo, it does not really contribute to fun that much in the long run as hyped. Rather when the dust settled, they contribute much more to frustration as it limit your play to the same counters (i.e. SLKR vs LV in 3v3). The set4 is now boring as hell because everyone has figured out and is trying to get more and more dodge% (or accuracy%). Set 5 is more interesting because of the stats. But it's just a matter of time when everyone got enough of what they need. Then the fun will stagnate. In this sense, CG made a bad decision prolonging the life-span of a DC set.