People regularly ask me whether Zoho One really delivers as an all-in-one platform. My honest answer after a decade of use: yes, but.
The strength is the depth. Bigin and CRM, Invoice, Books, Campaigns, Flow, Projects, Meetings, Assist, all from one source, one login, one data model.
The weakness is the breadth. You can get lost in 40+ apps. Start without a plan, and within two weeks you build yourself a labyrinth.
My advice: always start with the process, not with the app.