There's no way to answer the question. Even failure rates are suspect. Failure rates are typically a ratio of the amount of RMA's received for any given product.
Take for instance the Corsair CX-430. Extremely cheap psu that was decent for what it was and was intended for. Mass produced like crazy. It's actual failure rate was massively higher than its reported failure rate, Corsair counted failures as being returns, but as cheap as it was and as popular world wide, actual returns were minimal. If it broke, ppl just junked it and bought something else. A warranty return on a $30 psu and the turn around time simply wasn't worth the effort. The amount of returns vs amount of sales, the reported failure rate was tiny by comparison.
That didn't make it a good buy, a quality item, nor reliable and dependable for a gaming pc.
Also take volume into consideration, especially with reddit, YouTube, Tom's etc available. If you assume a 1% failure rate, seems small, tiny even, but if 1 million boards are sold, that's 10,000 unhappy ppl, many of which will post their woes. If only 100,000 boards are sold, that's a measly 1000 unhappy ppl, so a Lot less woeful stories hit the web, and the board looks like a much better deal in comparison.
Everything made by man has a failure rate, things break, happens, and there's no saying when. Asus has a decent track record, mid-grade or better MSI is good, Gigabyte same, ASRock was decent but seem to be slipping lately. I'd stay away from the budget offerings, to lower prices vs competitors, corners by necessity get cut more than is healthy.