Very few teams actually get laid off just because the product fails. The only time it's happened in Google's history was Google Radio Automation, where they brought on a bunch of people with very specific domain knowledge of the radio industry and then had nowhere to put them when they decided they weren't going to get involved with radio after all. Most of the time (assuming they don't quit), the team just gets absorbed into other products.

I assume things are similar in other large tech companies.

I'll posit that the real problem with big companies is the opposite: the price of failure is mild (you get reassigned to another team and get to do more cool stuff) and the benefits of success are also mild (you might get a promotion and an iPad or something). When your actions have little effect on the outcome, your actions tend to regress to the mean. In a startup, where failure means you starve and success means you never have to work again, you have a much bigger incentive to go the extra distance.

the reward for successful skunkworks at a large co is typically promotion (serious promotion to very high-paying, visible roles). That can be very rewarding for certain personality types.