Reasonably well paid doesn't alway hold compared to the cost (and supply) of housing in the bay area; new grads are often forced to share bedrooms even though they make $110k+. (This isn't
entirely tech companies' fault -- homeowners are not incentivized to allow housing growth to match new jobs, and California has been through many booms and busts in the past, so it is conservative in building out new capacity.)
Moderate hour expectations don't always hold during "crunch time"; Facebook and Google have large swaths of their employee base who are subject to the schedules of the large annual developer conferences (F8, Google Cloud Next, Google I/O). There have been internal mandates where employees were forced to work weekends for entire quarters.