Even if we're still far from the golden age, Dandadan (Science SARU; though I've heard the sheer effort bankrupted them) and the recent Witch Hat Atelier (Bug Films) are quite nice to behold.
Some modern romcoms like Kaguya-sama (A-1 Pictures) and The Dangers in My Heart (Shin-Ei) were nicely done too.
Things are obviously not going in the right direction, but the current accelerated fall in quality the consumer sees is more influenced by general unwillingness to spend and/or take risks from bean counting production committees.
The phrase 'production committee' appears only once in OP, with no discussion of the implications or how they work or how they change things compared to TV network monoposonies. Disappointingly superficial. It just repeats a lot of random salary or wage or working hour statistics and anecdotes without ever - puzzling for a piece in the Economist! - asking how this market operates, why it keeps going like this, and why rational self-interested actors avoid raising animator salaries or investing more in them or even increasing headcount, under circumstances like the current boom, which Econ 101 would predict results in a corresponding boom in animator populations and salaries...