Modern customers want real-time data and analysis. They want all of their information available on the web, mobile, sms, email, API. They want a modern technology experience.
A DOS program consuming data via EDI and Excel-based input is a good candidate for the worst technology to do these types of things.
I think most customer just want to know when their stuff is going to arrive - they don't need 'real-time data and analysis' (or if they do, they don't expect the guy moving the cargo to provide it for them).
Also, those DOS\cobol systems already made shipping so cheap you can get a 40 foot container (full of stuff) from China to LA for $1300.
They can't scale? They currently handle the whole world's shipping needs. That sounds like it scaled just fine.
You wouldn't, but freight forwarders typically don't move bulk cargo, they move containerized cargo. Bulk means the entire vessel hull is loaded with one raw materials commodity, like grains or minerals.
Companies importing finished goods absolutely do want instant, automated status updates on where their goods are at, because that information helps them load-balance their supply chain to keep their warehouses and stores stocked at the right levels and evaluate the performance of their contracted manufacturers and logistics service providers. Supply chain managers absolutely want scorecards and dashboards and push status updates.