10 bars makes no sense, and we used to have more intricate and demanding toolkits before, and people went through casual content just as fine. They just had to learn slightly different things than today, where today you spend 95% of your time learning about encounter mechanics in modern dungeons and whatnot, back then you spent time as a tank for example how to pull and position mobs (not behind you), as a caster how to manage your mp, etc.