Even if we're at the same home price / income ratio as 2008, a big difference is mortgage rates. In 2008 a 30 year was 5.5%-6.5%. Now it's 3%. So we aren't yet near 2008 levels of mortgage payment / income ratio
Not to mention that servicing these debts is getting more easy with time than before, as the dollar inflates. Not good in general, but predicting a housing crash due to over-leveraging is a bad thesis: people can easily afford to pay their mortgages. And besides, we all know "repeating 2008" is not a thing: financial crises happen when the thing nobody predicts occurs. 2008 is still fresh in everyone's memory, so you can be sure that particular kind of cascading effect won't be the catalyst for the next crisis. (It may rhyme, though.)