I think it was a decade ago when I heard someone describe Domino as "the mortar that holds together the bricks of all these separate monolithic & cloud systems we have to use." I think his description was quite apt, but even after 20y working in Domino I didnt know how relevant it was. So I focused some more on this part of Domino, & it proved itself. again.
The interface flexibility has been one major feature, hard to beat. While frameworks have grown from shiny toys to essential, Domino has allowed us to reach into them & change custom business apps to exploit them. Its more costly to develop there than I would've hoped, but not as costly as the half dozen rewrites nonNotes competitors have engaged in.
But underneath that, I've found quite a bit more flexibility than I expected. I ran into a situation recently where a collection of different departments (bricks) had certain ways they each had to operate. Each was most optimized, operating differently. And the corp managers needed only some bits to rise to enterprise level. After 30y in this, I was even surprised at Domino's ability to flex to each need. Profiling features, sequencing approvals, profiled formulas to set up access controls, profiled defaults ... Domino showed features once again that other platforms simply dont have available. Unless you're writing your own site software.
It's an impressive bit of software. I know devs dislike it "as emaill"; it never was just email. Devs also don't like its nonstandard server; over the decades it's often served better than standard.
I buck the trend. Domino's value may rise. Domino often entrenched itself when worker efficiency was at a premium. it also shines when the bricks of the regular DB and business systems don't fit together well. It's simply best at that. And it can be a quick platform for development, for developers willing to understand flexible NoSQL systems and identify the right features for the functions. If the product gets support for its talents, it could find its niche here; but it still depends on its owner, IBM.