It was 1998, and it wasn't that common, but in tech it wasn't impossible. For Pixar it was hard because of the size of the files, but otherwise wasn't all that hard.
I occasionally worked from home in 1998. The biggest impediment was network speed -- at work we had 10mbps and sometimes even 100mpbs. But at home all we had was dail up or if you were really lucky, DSL, which was 0.384mbps, so 30 times slower, and also latency was a lot higher.
So you were very limited in what you could do. Mostly it was just email and remote access ssh with tmux, where you sometimes had to deal with really high latency.
I worked remote in 98. Depending on your location it wasn't quite that bad. I had SDSL at 1.54 mbit in those years and it was workable. You could get ADSL here then too for a bit more download at the cost of upload and overall connection stability. Granted, I was doing gamedev which had smaller assets than a film, but you could manage a bit more than just a terminal a lot of places.
My employer paid for ISDN in 1999 and I thought I’d reached nirvana. It wasn’t dramatically faster than modem, but an always-on connection directly to the corporate network was quite handy when getting paged at 3am.
In this case, if you were an animator, you could still create models/animations, but you wouldn't be able to sync up with the rest of team on a daily basis. Perhaps a little frustrating, but with decent communication it would have been manageable.
Unless you were an independent entity that could do most of your work over the phone with only occasional in-person meetings (e.g. certain kinds of salespeople and some artists), it was very rare.
It only happened in this instance because the person in question had a newborn baby and I guess maternal leave wasn't a thing at Pixar back then.
I occasionally worked from home in 1998. The biggest impediment was network speed -- at work we had 10mbps and sometimes even 100mpbs. But at home all we had was dail up or if you were really lucky, DSL, which was 0.384mbps, so 30 times slower, and also latency was a lot higher.
So you were very limited in what you could do. Mostly it was just email and remote access ssh with tmux, where you sometimes had to deal with really high latency.