When CP/M etc. launched it was not a problem that they maxed out at 64kB of RAM, because that was $tens of thousands worth of memory.
When XP launched, it was not a problem that it maxed out at 3-and-a-bit GB of RAM, for exactly the same reason.
CP/M launched in 1974, I think, and was a current OS until say 1984 or so when the PC-AT came out and MS-DOS systems could address a whole megabyte of RAM and it was clearly game over for Z80 boxes.
(Aside: my 3rd ever personal computer was an Amstrad PCW9512, a new CP/M machine launched in 1987 when I was 20.
It shipped with 1/2MB of RAM and could take more. CP/M 3, AKA CP/M Plus, could use the rest as a RAMdisk. This is again analagous to LIM-spec EMS on DOS on 8086 class kit, and PAE on x86-32 servers.)
The point here being, it began to be a problem for rich folks and power users long before it was a problem for the mass market.
But the user base of the old OS was a problem that hindered adoption of something new and better that fixed the issue.
CP/M overcame being unable to handle >64kB of RAM, but too late to help. DOS was taking its place. The big-name apps (WordStar, dBase, SuperCalc, etc.) were rewritten for the new OS.
DOS overcame being unable to use a 386 and >640kB of RAM, but too late: Windows was taking its place. The big name apps (1-2-3, WordPerfect, FoxPro) were rewritten for the new OS.
Windows 9x overcame being unable to use >256MB of RAM or gigahertz-class CPUs, but too late: XP was taking its place. The big name apps... just got updated.
Windows Server 2003 (XP for servers) overcame being unable to use >3.5GB of RAM, but too late: Windows Server 2008 R2 (Win 7 for servers) went 64-bit only and replaced it.
When CP/M etc. launched it was not a problem that they maxed out at 64kB of RAM, because that was $tens of thousands worth of memory.
When XP launched, it was not a problem that it maxed out at 3-and-a-bit GB of RAM, for exactly the same reason.
CP/M launched in 1974, I think, and was a current OS until say 1984 or so when the PC-AT came out and MS-DOS systems could address a whole megabyte of RAM and it was clearly game over for Z80 boxes.
(Aside: my 3rd ever personal computer was an Amstrad PCW9512, a new CP/M machine launched in 1987 when I was 20.
https://news.ycombinator.com/item?id=36649261
It shipped with 1/2MB of RAM and could take more. CP/M 3, AKA CP/M Plus, could use the rest as a RAMdisk. This is again analagous to LIM-spec EMS on DOS on 8086 class kit, and PAE on x86-32 servers.)
The point here being, it began to be a problem for rich folks and power users long before it was a problem for the mass market.
But the user base of the old OS was a problem that hindered adoption of something new and better that fixed the issue.
CP/M overcame being unable to handle >64kB of RAM, but too late to help. DOS was taking its place. The big-name apps (WordStar, dBase, SuperCalc, etc.) were rewritten for the new OS.
DOS overcame being unable to use a 386 and >640kB of RAM, but too late: Windows was taking its place. The big name apps (1-2-3, WordPerfect, FoxPro) were rewritten for the new OS.
Windows 9x overcame being unable to use >256MB of RAM or gigahertz-class CPUs, but too late: XP was taking its place. The big name apps... just got updated.
Windows Server 2003 (XP for servers) overcame being unable to use >3.5GB of RAM, but too late: Windows Server 2008 R2 (Win 7 for servers) went 64-bit only and replaced it.
The wheel turns, and all is one.