I don't think you have an operating understanding of legal tender. No widely-applicable law in Canada or the US requires businesses to accept bank notes to settle a transaction. See e.g. https://globalnews.ca/news/6878824/legal-for-businesses-to-r... and https://www.federalreserve.gov/faqs/currency_12772.htm . Some municipalities and states have added laws requiring cash acceptance, but it's not as simple as "it's legal tender" or "you can do it in Canada."
There's a difference between the letter of the law and the word of the law. Having experienced both places I can say there is a difference in how things are run and regulated and if they call it legal tender or whatever it doesn't matter. As a customer it does matter because I end up paying the junk fees so please don't patronize me for saying it.