You can find a hosted “cloud” service for pretty much anything these days. When I was still working at Microsoft, I used GitHub regularly, and I've used a number of other Microsoft services. That said, it's possible to host most of your own stuff pretty easily these days.

My own projects are all hosted on my own installation of Gitea. Hosted git services like GitHub and BitBucket are useful if you don't want to host your own, but rolling your own solutions for pretty much everything is better in the long run.

The one exception is email. Running your own email is a massive pain - and very difficult if you're running a server out of your physical home. If your hosting provider or DNS registrar offers email, it's worth letting them handle the heavy lifting. If you want business features (i.e. calendar sharing, global address lists, delegation, etc.) the best option - even in 2022 - is Exchange Online (or Microsoft 365, if you need additional services).

I don't say this because I used to work at Microsoft. I say it because it's just true: no other platform has solid Outlook integration, and no other platform is supported on everything ever, because Exchange has been around for so long now. Outlook and Exchange are still king for business communications.