The definitive biglaw vs. BB IB debate!

Hey guys, 

I know that there have been posts in the past about biglaw vs. BB IB, and the consensus here is that biglaw is for people who failed out of high school while unable to add numbers and are looking for a re-do in undergrad for a big bucks job. WSO also says that IBD also pays exponentially more than biglaw and that the "M&A transactional associates work for us and our deals hahahaha." They even say that biglaw transactional law is infinitely more boring than excel modeling... However, I have a big qualm with this:

If making equity partner in biglaw takes 8 years and even freshly-minted equity partners can pull $2m (non-equity partners can still easily make $750K a year; keep in mind this is at age 33, so assuming opportunity cost of law school, 11 years), and it takes 15 years for BB IB MDs to even get close to a single million, let alone two, isn't biglaw a better financial deal? If biglaw associates work 12 hour days, don't BB IBAs work 16 hours?

And ik that equity partner is a BIG BIG if and only if question (only 50% of those who try for 8 years pull it off, barring the 75%+ of associates who leave or get kicked out), but isn't the risk of 11 years + $2m (and this salary can go up 10x in 20 years) with slightly lower work hours better than 15 years + on average 20 more hours of work a week + guaranteed $1m? 

I'm probably getting something wrong here, but I don't understand how biglaw is equal, let alone worse, than IB if they have less hours with more money and less time. This may be a blanket statement and poor generalization, but biglaw associates by and large aren't as intellectual as IBs (IB analysts popped off in high school itself) with a much much easier interview life, so the average IBer could probably get equity partner anyway.