First, the company has always been extremely supportive. Many employees have been working from home exclusively for years and nearly all of us WFH from time to time at least. The processes and expectations are well established. Engineers have always been supplied with a laptop in addition to their workstation, so WFH has always been immediately possible for everyone. You get your pick of hardware, but all the systems and services and processes have been optimized to make it reasonable (not just possible) to get serious engineering work done with nothing but a Chromebook. I've seen many programmers working _at the office_ from a Chromebook because they liked the interface. But for most of us... it's not optimal.
Corp work has to be done on Corp-owned hardware. This is enforced by technical controls that can't readily be circumvented, so even if you have a great computer at home, you'll be working from your laptop. Many of us at the kitchen table. Unless, of course, you've gotten a corp-issued rig in your house... which can't have happened in the past couple of months because the computer hardware supply chain in China has been shut down for a long time. Think you'll just go buy a nice monitor from Best Buy and dock it with your laptop? You weren't the first to think that; computer monitors are sold out across the city (having 4 giant tech companies all go 100% WFH at the same time will do that).
At a team level, it's been a mess. Productivity is definitely not up. We still get a lot of stuff done and we haven't adjusted any of our forecasts, but coordination has become a whole lot harder. Sure the company has been generally ready for this for a long time, but as individuals we were a bit blind-sided by the suddenness of it. Oh, and the local school district has gone "remote-learning" as well for this month (think WFH, but for 9-year-olds), so local parents are doubling as home-school proctors. It's not a distraction-free environment.
Thing is, we wouldn't have offices if it we didn't work more efficiently there. It's not like working from home is something foreign to us; like I said, we all do it as often as we like. Each of us maybe a couple of days a month, as circumstances require. But sending everyone home at the same time, that hasn't been the utopia it might seem to the casual onlooker.