Its worth noting that in retrospect PageMaker won the DTP wars of the 1990s.Quark XPress was the industry leader in that period (most users had a love-hate relationship with it). There was also Ventura Publisher but that had the least market share.
Adobe acquired Aldus and PageMaker became an Adobe product.
Quark were thought of (and reportedly thought of themselves) to be invincible in their DTP software market penetration/moat. Sounds familiar?
Their pockets were deep enough then that they even offered to buy PagerMaker from Adobe ... to bury it.
Instead, Adobe released InDesign and while a rewrite, it is clear to anyone who used PageMaker that the whole UX and ways of working was/were taken 1:1 from PageMaker, not XPress.
This was quite a daring move.
Adobe didn't have the standing yet in DTP to know if people would switch.
Especially since there were many software companies who had built an ecosystem of XPress plugins (very similar to the ecosystem if plugins that cemented Photoshop and later AfterEffect's positions as industry standards in image editing and motion graphics).
And for which Adobe wouldn't have a competing offer when InDesign shipped initially; and likely for years to come.
On the other hand, XPress was known for being unstable to the degree of being a PITA to work with. Even people who much preferred its UX over PageMaker were aware.
Still, I recall XPress users mocking InDesign and saying it would go nowhere.
Within a few years though, PageMaker's spiritual successor proved them wrong.
Sadly InDesign is now a joke.
Six years ago I had to use it for something simple like exporting 500 letter template instances to a single PDF for printing (where each letter gets the address/addressee replaced).
It couldn't do it. It would crash every time. I found bug reports and forum threads from years ago where people complained about this.
I managed to eventually export it as 'PDF for Web' as I found a reddit thread were someone noted this was hitting an entirely different PDF export code path.
In short, today, without serious competition for years, InDesign is just a cash cow for Adobe. Getting as much love as Quark XPress did, before its eventual demise.