It isn't. Riding the ferry is a pain in the ass. Boats are slow (or it is too much of a nuisance). High traffic makes it even slower.

Source: live in a city with shitloads of canals and ferries.

I was once in the running for a job at a place that was on the banks of a lake and included a boat landing. Learned that there was a house available within my price range right across on the same lake. So I started having real conversations with my wife about us getting like a jet ski for me to commute across the lake to work.

Didn't get the job. Was bummed.

I think the main advantage would have been getting non urgent freight off motorways as bulk efficiency is the big perk you get with boats.

If you want to boat into work every day Toronto has that option available all year from the islands. Another perk is living in a car free & wooded neighborhood 5-15 minutes away from downtown/harbourfront. Lots of people also live on boats on the Toronto islands, drive their dinghy into town during the summer and then dock at one of the harbourfront marinas in the winter. (Just watch out for the crazy water taxi drivers!)

I'm a little jealous of people in England who live on narrowboats on their canals.

And also jealous of the multi-use trail network on what used to be the tow paths, for that matter.

I seem to recall reading about Swiss workers swimming home in the river after work, the current carried them the right way and it seemed brilliant

As someone who used to ride a boat to work every day, it fuckin ruled and I miss it

I prefer rail in its various forms. Way faster and cheaper. Canals are absolutely amazing at one crucial thing: moving mind boggling amounts of bulky low value goods for a fraction the cost of rail. The mississippi river system was no joke an american superpower (and still is) for a looong time. You can move grain for thousands of kms for the same price it would cost to ship it 150 via rail.