Novels didn't exist as we currently think of novels before the printing press. A lot of novels were serialized in magazines and authors paid by how much they wrote. Now some of that creative and gotta-earn-money energy goes elsewhere, because we invented a different mass distribution method (internet) that does text, audio, and video all at once.

I don't worry that the decline of the literary novel means anything negative about the present era. Still got a lotta new words and sounds and images worth reading, listening to, seeing.

I am also sure that a lot of the "significant" creative work from our time that future historians will dwell upon will be popular mass culture that engages with recent changes in technology. Shakespeare falls under that definition!

This may be leaping ahead of where you're going with this, but: Earlier in life I went down the line of thinking that society/arts etc is getting spiritually or creatively worse compared to some earlier era I valued and it's important for me to resist this and notice how contemporary trends are bad. All I found down that path was a lot of loneliness, suffering, and being oblivious to great things that were happening around me. I only did creative work I still feel good about after I stopped feeling so negatively about the present era from an arts/culture perspective and started enjoying and being curious about contemporary arts/people around me. I never consciously decided to change but what finally worked for me was trying a lot of new creative stuff on purpose that I wouldn't normally think I would enjoy and giving myself permission to have a great time even if it something first struck me as silly, bad, not my thing, etc. I was able to do this and it only deepened my love for any old, obscure, highbrow, acquired taste arts I already valued.