My own view as a writer and artist, is that there's a relatively consistent amount of creative innovation being done at any given time. It's access to it and promotion of it that varies.
Whats happened since the 90s is that rents have consistently risen - meaning physical scenes are enormously less likely to emerge, and (as the author rightly points out) algorithmic recommendations have both isolate people in their own bubbles of past preference and privileged big content. Big content has been selling the transmedia vision of wholly owned and diversified 'media properties' pretty consistently since then.
However - artists gonna art. Brilliant writing is out there, unpublished by the narrow coterie of MFA grad, politically unipolar editors running grant funded publications. Brilliant filmmaking is out there - and actually experiencing a renaissance thanks to cheap tools; but getting a mid budget opportunity, the pathway from zero / microbudget to mainstream director is now close to impossible. Incredible new music is out there, but spotify doesn't pay, and a social media audience is by definition drawn to repetitious, unchallenging, immediately accessible soothing or shocking material.
It's not the culture thats stuck, it's the media.
Also enormously relevant to all this is the spaces artists can display their work, and engage with one another. In Dublin in the early 2010s this played out rapidly. After the financial crisis there was a period of about four years where rents dropped precipitously. The explosion of art shows, participatory art spaces and public creativity was extraordinary. A city of 500k people had more than 40 open active public art spaces. It's all since disappeared - but the artists, performers and organisers who made it happen were alive before and lived on after. They just don't have the affordances necessary to create / promote that kind of work. Namely physical public facing spaces located in the city.