Ski Bags on Air Canada

Skis (including poles):

One or more sets of skis (snow or water) carried together in the same container count as one piece of checked baggage. See exception at top of Ski and Snowboard section.
Skis and poles must be packed in a rigid and/or hard shell case specifically designed for shipping.
If carried separately, a set of ski poles will count as one piece of checked baggage.
No oversize charge applies to skis. But, any overweight charges will apply
See ski boot bag information above.

https://www.aircanada.com/us/en/aco/home/plan/baggage/special-items.html#/

If you have questions, a call to the airline seems appropriate

As suggested above, contact Air Canada for clarification but realize that you may be subjected to a different interpretation when checking in your skis.

One (my) interpretation is that Air Canada will not accept liability for damage if you do not use a hard shell ski case. We use to travel with Hawaiian luggage (banana box) where the agent would have us sign a damage waiver.

That said, we have use plastic shell SporTube ski caes. The Series 2 SporTube holds up to 4 pairs of Cross Country skis (2 pairs of Alpine). So far the only loss exoerienced is the TSA losing the clevis pin that secure the two piece cae.

https://www.sportube.com/category-s/1962.htm

One benefit of the SporTube case is that they have wheels at the bottom of the hard shell case so that you can pull the skis like wheelie luggage. The REI "catalogue" has a better description and photo of the wheels: https://www.rei.com/product/638691/sportube-series-2-hard-sided-wheeled-ski-case
MEC also carries Sportube cases: https://www.mec.ca/en/product/5038-461/Series-2-Transport-Case

Considering the airline, this must come up all the time. Isn't it likely they would have long cardboard box/tube thingys you could slip your soft bag into?