The most important feature is fit and comfort. That's personal. Next they have to be quick drying. You can pretty much stop here and you are good.
But if you feel like getting into the weeds, the important qualities in a canoeing shoe vary based on the type of travelling you do. It seems the most popular shoe for canoeing are Crocs and Keen sandles. These are both at the bottom of the list for me. One step below any 3/4 high Goretex boot.
I like to have adventurous trips. I don't base camp. My feet are often wet. I run white water. I bushwhack. I like seldom used or rougher trails. I usually travel for long days.
The grippier the shoe the better. But not all grip is the same. Shoes with big durable lugs are great for rocky and rooty dirt trails. But do next to nothing on wet rock. Wet slippery smooth rock is the most likely place for slips and falls. For wet and moss/algae covered smooth rock, you need soft rubber soles with siping. These types of shoes will not last like the big durable lugged soles. But are much grippier and will save you from falling. Saying you like Contagrip or Vibram is meaningless. These are brands and both brands can tweak their rubber and designs to suit different needs. In my opinion, you want soft sticky rubber that has been siped.
Another important feature for me is protection and security. I like the shoes to have a good toe guard to protect my toes when banging into rocks and roots both in and out of the water. I also like the shoes to be slightly higher to offer some ankle protection. The slightly higher collar also prevents them from coming off in mud or white water dumps. But, they can't be so big and bulky that they give you difficulty getting your feet under a canoe seat or present an entrapment hazzard.
Finally I like my shoes to be lightweight. Both when wet and dry. For a shoe to be light when wet it has to have built drainage and the material should not absorb water. There is always a compromise between weight, grip, durability and support. My ankles are still strong enough that support isn't a big concern. For me lightweight, quick draining, hydrophobic nylon uppers and soft grippy soles take precedence over durable leather or waterproof synthetic uppers and dense rubber soles.
Last, I change my shoes out seasonally. Early and late season white water trips I use a very warm boot. It is a huge compromise. Big and bulky and very heavy when wet. I don't love them but they keep my toes from freezing.
Ice out white water trips I use NRS Workboots. The rest of the year Astral Rasslers. Other shoes I like include Astral TR1 Merge, Soloman Speedcross, La Sportiva Ultra Raptors, 5-10 Canyoneers and Baffin Amazon.
