It depends. If you need basic word processing, spreadsheets, presentations, and email, you can definitely get by with alternatives. If you want more advanced functionality, you’re more likely to run into limitations or just things that work differently than what you might be used to. Microsoft 365 is not better in every way, but it’s a strong contender.

I suspect the familiarity and compatibility probably cinches it for a lot of people. Honestly, the convenience and familiarity are valuable, even if you and I would prefer open source options were more popular.