>Dell+Windows 10+Office365 laptops
Bet they were under spec'd ie. a typical Dell mid-range business laptop from 2010 running Win7 and Office outperformed it.
I know the ones, one of my local school's have been mandating since 2013 have been so useless that kids avoid using them and only carry them around school because "its the rules" and parents purchased laptops/PC's more suited to running Office concurrently with Spotify, YouTube etc. which naturally stayed at home. Fortunately, the school deal did let parents install Office365 etc. on the home system(s).