Though I did answer the linked question, I thought to quote parts of this article.
Source: The RRSP advantage, by David Hodges, February 6th 2015
[John] Storjohann ['the 58-year-old Calgary project manager'] is keenly aware of the two main advantages of RRSPs: the tax refund when you make a contribution, and the tax-deferred growth until you make withdrawals in retirement. These make RRSPs ideal for those who expect to be in a lower tax bracket when they stop working—which will be the case for most Canadians. For those in the highest tax bracket today, the RRSP is a no-brainer. That’s why Storjohann’s always surprised when he meets people pulling in good incomes who think TFSAs stack up better than RRSPs. “People just don’t understand how these accounts work.”
This is the most common objection to RRSPs: people simply hate the idea of paying taxes on the withdrawals. Money taken out of a TFSA, by contrast, is tax-free, which sounds far more appealing. But that logic ignores the fact that you receive a tax refund when you put money in an RRSP, while TFSA contributions are made with after-tax dollars. So for the Fosters and other Canadians weighing this decision, it comes down to whether it’s better to pay tax now or later. And that’s not an easy question to answer.
Both Hamilton and Kirzner say that anyone earning more than $50,000 is usually better off prioritizing RRSPs over TFSAs. While both accounts allow your investments to grow tax-free, the tax refund makes the RRSP more attractive for high-income earners. ...
That, in a nutshell, is what makes RRSPs better than TFSAs for higher earners: Not only are you taxed on your money years later, but because you’re in a lower bracket when you retire, you’ll pay less tax too.
When your income is between $35,000 and $50,000, the long-term tax differences between RRSPs and TFSAs become negligible, says Malcolm Hamilton. In that salary range, “just being able to put money aside in either an RRSP or a TFSA is great.”
But RRSPs can still be a better choice for reasons that don’t involve tax deferral or refunds. In his new book, Wealthing Like Rabbits, author Robert Brown makes the case for favouring RRSPs over TFSAs most of the time because the former usually means less temptation to access your retirement savings early.
Footnote: This 2012 CBC.ca article intelligibly explains RRSPs, free of jargon.