Can a Canadian company be the US importer of record?

This question gets hedged answers because the honest answer is conditional. Understanding the conditions is what lets you decide, rather than waiting for someone to say yes or no.

What being importer of record means

The importer of record is the party responsible to customs for the entry: for declaring the goods correctly, for paying duty and fees, for keeping records, and for answering if the entry is questioned later.

It is a role with obligations, not a checkbox on a shipping form. Whoever holds it owns the classification accuracy, the valuation and the recordkeeping.

What a foreign company needs to hold the role

Broadly: a way to be identified for customs purposes, a bond appropriate to the import activity, and the practical ability to meet recordkeeping and response obligations from outside the country.

Each of those is satisfiable. Each also has a cost and an administrative footprint, and the combination is what determines whether this path is sensible at your volume or merely possible.

Where it tends to work and not work

It tends to work when you are importing in bulk to a US 3PL, your product range is narrow and well classified, and your volume justifies the bond and administration.

It tends not to work when your catalogue is wide and poorly classified, when you need a US-domestic commercial presence for other reasons, or when your volume is low enough that the fixed costs dominate and parcel-by-parcel shipping is still cheaper.

The question to answer before this one

What do you currently spend per US order on duty, brokerage, freight and returns? Without that number you cannot evaluate any alternative, because there is nothing to compare against.

Establish it first. It frequently turns out that the answer to "should we become importer of record" is "not yet, and here is the volume at which that changes" — which is a far more useful conclusion than a yes or no.