Please see the question in the title. Consider merely Corporate Bond ETFs trading in Canada with a minimum credit rating of BBB.
My daredevil grandma in Toronto bought 70% equity and 30% bond ETFs, and all of the 30% is VAB (Canadian Aggregate Bond Index ETF). She knows this asset allocation is venturesome. But no sweat - she has enough savings in HISAs.
Henceforward (like when she re-balances), she's thinking of buying merely a Canadian Corporate Bond ETF with an MER < 0.4%, no more of VAB. Consider VCB and ZCB. All their holdings are large-caps' bonds, and Canadian large-caps are a touch riskier than Canadian governments. But isn't the scorn for Corporate Bond ETFs in the Reddit post beneath overboard?
As you move further down the investment grade spectrum, the debt behaves a lot more like equity.
General advice is that if you want to take more risk, you can allocate a higher percentage to equities. And let the bond portion of your portfolio do it's job.
You need to rethink that logic.
* Corporate bonds give you exposure to corporations - where you already have exposure in your stock holdings.
* If a Treasury bond allocation is not risky enough for you simply reduce the % allocation. Simple
Most importantly ... as Wizard says below, the whole point of allocating to low-return bonds (and losing the higher returns from stocks) is to get an asset that rises in value during the major stock crashes you could not handle otherwise. But corporate bonds do NOT rise in value ... they decline like stocks.
So you don't get the protection during the crash, AND you lose profits in all the years there is not a crash.