Actors leave their popular TV shows behind for numerous reasons.
Whether it be a veteran actor wanting to spend more time with their kids after several seasons of work or a young star dreaming big of Hollywood roles, actors can make what they believe to be informed decisions at the time to pursue other options... only to end up regretting it.
That's because sometimes those future prospects don't always work out they way they hoped, and instead actors live to regret leaving behind what sometimes ends up being their most acclaimed role. The fear of typecasting is a real threat in Hollywood, and many of these actors were never quite able to shake the shell of the acclaimed role they quit. Still, it can take many years of trying to break out before they sit down with an interviewer and admit their regret at leaving their show behind.
Of course, some of these actors have still gone on to achieve great things in film and television, and in rare cases have managed to completely reinvent themselves separate from their popular shows. But often these attempts crash and burn, and they all have one thing in common: their informed decisions ended up not being as informed as they believed them to be.