I think you're right that legacy, mindshare/knowledge etc played a big part in it, and I'm sure Windows is much better with this stuff now. Although the handful of studios I've been to in the last few years were still running Macs, but again maybe that's just mindshare.
A funny thing I realized recently while trying to setup OBS for video conferencing on my Mac at home (I work as a teacher occasionally): There is no way out of the box to capture system audio, you either need to do it through external hardware or use a hacky solution like Loopback. On Windows, this "just works".
In other words, you and OP may both be right. Three absolutely massive transitions at apple between your era and theirs: hardware, software and management quality.
Your bad luck was that you bailed out of the MacOS audio subsystems just when they started to get good.
Any user who needs to perform audio with any computer will need a soundcard in order to have any sort of decent quality, for #1 Decent quality inputs and outputs #2 The correct input and output types like XLR (or fibre optic or whatever) #3 Acceptable latency for live performance.
Soundcards are available for mac or windows, the makers provide drivers which deal with the "Audio and MIDI stacks". From a users perspective theyre both fine. After that, you care about the machines performance, CPU, how much RAM, how fast is the RAM, how fast is the SSD.
MS tried a bunch of tech in the past (WinMM, MCIWnd, DirectSound, WaveOut, WASAPI, XAudio2, etc), but none of them ever worked for professional Audio.
The proper solution was always to use ASIO, which is third-party technology by Steinberg. It works but it's not integrated with Windows: it goes directly to the audio interface, bypassing stuff in the Kernel.
This bypass causes some limitations, such as not being able to use the system mixer (which prevents from using media players or multiple audio apps), or sometimes having different audio-interfaces not work well with each other.
There are workarounds to those issues, but they have to be handled by the interface manufacturer when writing the drivers. Also, you can't have low-latency with built-in soundcard unless you use something like ASIO4ALL, which is not super stable IME. This sucks when you want to work on-the-go with headphones.
Of course, it can be very stable when you use the right combination of DAW, drivers and sound interfaces, but when you don't you have problems.
On macOS and iOS? CoreAudio is native and it has super low latency by default. It's mostly plug and play and all apps use it. It even provides APIs to use Audio Plugins or reroute Audio, so DAW writers don't even have to write it themselves (unless they want to). Do you have multiple Audio/MIDI interface? In macOS there's a built-in app to "link" them together.