It became feasible to switch to CSS layouts for complex websites and apps in the early 00s. How early depended upon your target demographics and skill set. Lots of people who didn’t want to learn new ways of doing things carried on using table layouts long after browser support demanded it. I was using CSS sparingly from 1999 onwards and ditched table layouts in 2002, but I was ahead of the curve.
Same here, we resigned our site in early 2003 with CSS layout. Late adopters would snicker a bit back then, seeing it as chasing a fad or being too hipster.
Out of all similar situations, where I may have been an early adopter of a technology or method for reasons, using the web platform and following standards has probably been the one I least regret.