It starts sensibly. Stock lives in a spreadsheet because a spreadsheet is fast and everyone knows it. Orders come in by email and phone, so they go in a second spreadsheet. The webshop has its own admin panel. Deliveries get arranged in a WhatsApp group with the drivers. Invoices are run off in the accounts package. Prices for the trade sit in a shared doc. Each tool was the obvious answer to the problem in front of someone, on the day they reached for it.
None of them is wrong on its own. The trouble is that a nursery is one business, and these tools each believe they are the whole story. The webshop doesn't know what the wholesale side just sold. The stock sheet doesn't know what's reserved against a quote. The accounts package doesn't know a delivery bounced. Every tool holds a sliver of the truth and none holds all of it.
So someone has to be the glue. A person becomes the integration layer — copying numbers from one screen to another, chasing the version everyone should be using, and holding in their head the parts no system records. That work is invisible until they take a holiday.