All multi-platform Office apps (i.e., not Access) allow multiple account integration, except To-Do. It's been requested and voted for since the beginning on UserVoice, to no avail. Microsoft has enabled multiple accounts in To-Do for Windows and Android, but not iOS and Mac, although multiple account integration on those platforms works flawlessly with other Office apps. This makes To-Do useless for anyone with busy lives both at home and at work.
LOL the way MS is handling ToDo requests (it doesn't) is the primary reason I am considering replacing my W10 laptop with a MacBook once the time to upgrade comes. While Apple is even worse than MS when it comes to user requests, at least their services work extremely well across their devices. Since I am already forced to keep my personal tasks in Apple Reminders so that I could share them with other family members and get notifications while I am signed into my work Todo account, might as well take the next step. I love the idea of MS services, but the implementation is often just... not all there.