Agreed, but the overall savings would still be significant even if IT costs increased. Capital costs for new equipment might be an issue if companies are using IT kit "not fit for purpose"
Capital cost is a major issue.
Take our network and what was involved to switch to home working
around 2500 new laptops with more to come
similar number of new licenses for Microsoft Office
licences for sercurity and other software
massive upgrade in our data bandwidth - something like 20x so far and need to up it again, Virgin love us...........
enhanced servers to allow for the increased number of VPN connection
look at the increased data load - an example is Skype for business. Sessions have gone from 800 / week to something like 2000 / day. Some of those are phone call replacements, some are Microsoft "Teams" meeting. But just to host that lot required a lot of back end work
Another aspect was the need to route the Cisco internal phone network through our network and out via the VPN to the at-home users - yet more data load
Labour demand was large - 12 hour days, 6/7 day weeks for the IT teams putting all this together, while at the same time having to cope with the viral risks - which hospitalised a team of four on one site, while killing a couple of guys doing the same job for another trust.
One good thing - its enabled the removal of any remaining Win7 machines. As for XP, the only ones I've seen for years have been dedicated CCTV installations, and also controlling PCs for x-ray and scanning machines. All air-gapped from the network. FWIW I do know of a Win98 machine at one hospital trust - it holds the kitchen menus and the software can't be upgraded, while some hospitals use standalone Win2000 machines to control PCR analytical systems - again because the software can't be upgraded