On the Mac Plus and other Macs in a similar chassis, yes, there wasn't much room to move windows around, but it was still possible. Apple also released several larger Mac displays (around 16 by my count) prior to 1995, including two 21" models (in 1989 and 1991, respectively). Workstation-like window management absolutely happened on Macs in the late 80s and early 90s.
(I remain amazed at how people even today will argue like this trying to avoid talking nice about MS. You're misconstruing the point, seemingly deliberately.)
Sure, on $15k ($30k in 2025 dollars) Mac II's. See also the answer elsewhere about NeXTSTEP being a player in this space.
No one was doing it in the consumer space, no consumer knew about that stuff, Linux consumers on their 14" 800x600 monitors sure hadn't see it. And to repeat yet again, Microsoft Windows 95 landed like a bomb in this community and changed everything. And it happened very fast.
The thing that the earliest Macs lacked was multitasking (outside of desk accessories). It took until Hertzfeld created Switcher before you could run more than one full Mac app at a time, and even that required 512K RAM.