(And I mean the desktop version. O365 is dumbed down half-way to Google's Office Suite level - which is cool for an occasional document or spreadsheet, but is lacking both features and efficiency for professional use.)
99% of my job requires nothing more than a web browser and a terminal with a SSH client. The remainder is mostly Wireshark.
Indeed it does. At her last-1 job, my wife could probably do most of the spreadsheet-related stuff in GSuite, except for that one spreadsheet that brought desktop Excel to its knees, and would totally explode the browser if you've ever tried it.
My experience from watching other people and occasional summer jobs is mixed. Some of the stuff you technically could manage on GSuite. Others you wouldn't, not because the files were too big/complex, but because the office computers were underpowered.