Windows 2000 was memory protected, and still had very modest hardware requirements. IMO the pinnacle of Windows UX, everything after that was downhill.
Win2k was peak windows. Though, it did need a lot more RAM than 98 did - it was happy only at 128mb, and 256mb was optimal.
Meanwhile, 98 could run most things all day at 64meg.
98's swap and caching agent was definitely not as good as 2k though. You absolutely had to reboot at least daily or the chance of hitting swap would only increase upwards.
All of my computer muscle memory is from Windows 2000. It was surprisingly accessible for it's time. Modern macOS still can't use the tab key correctly to tab focus between certain buttons, inputs and actions.
Windows Server 2003 with Interix was my daily driver for a few years. That was my "peak Windows" moment. It had a fast UI, could run software meant for XP, and I could compile a ton of POSIX-targeted software.
I always thought that this was vaporware, something that was listed in books and white papers but never seen in the wild. Good that it eventually arrived.
It is true, yet multi language support was near non existent, you had a special version for CJK, digging the registry was a common thing, good luck trying to read a linux partition and an emulation of a bash shell would be the best you'd get.
All in all I respect the nostalgy, and see how many people would still be fine with these restrictions. I personally wouldn't want to go back to these day short of being paid a few trillions.
- full UTF-16 support, l10n was painful on purpose for licensing / differential pricing — Microsoft simply didn't want people in rich countries to grab MX/PH licenses and swap over to English/Japanese/other G7 languages. With the far more aggressive licensing schemes of XP and later that was less of a problem.
— Full IFS support, to allow arbitrary, high performance filesystem drivers. Win2k was just obsolete by the time those were mature enough to really use
— A full NT kernel with support for swappable userspaces. The POSIX subsystem was deliberately crippled by MS to fulfil federal requirements without allowing real interoperability, but nothing would've stopped them from doing a WSL1-equivalent BSD/Linux subsystem. (WSL2 would've been impossible simply because hardware virtualization for x86 didn't exist)
None of those features really need the full array of modern bloat, where even hitting the start button can take seconds to refresh all the adverts.
98's swap and caching agent was definitely not as good as 2k though. You absolutely had to reboot at least daily or the chance of hitting swap would only increase upwards.