I play online tournaments (although not as often as I was in past year or two due to time constraints) for the chance at big scores plus the flow of tournaments to me is a lot more exciting than cash games. There's a distinct beginning, middle, and conclusion. There's placing and rankings. There, for whatever reasons, is more prestige and public awareness/fandom around tournament play too.
But I generally prefer cash games for my bankroll grind challenges online and also live cash games.
You can easily go dozens of MTTS without even a min cash let alone a final table score. And you can spend hours playing only to bust out. With cash you can come and go as you please and as others said I think you can learn and improve in poker a lot more through cash games.
MTTs def require skill and strategy but they also I think have easier pre flop and post flop decisions in many cases than cash games. I think luck also plays a much bigger factor in MTT outcomes than cash game outcomes. You've sometimes got to make moves in MTTs that if you made the same move in cash games you'd be making massive mistakes. There's no pressure in cash games of increasing blinds, antes, and climbing up the payout structure.