The two piece suit is the foundation of professional dressing for most men and the reason it’s held this position for so long is that it genuinely works across a wider range of situations than almost any other garment combination. The jacket can separate from the trousers and work as a blazer over different trousers. The trousers can work with a different jacket or a knit. When they’re together they create a coherent formal look. This versatility is worth thinking about when you’re buying because a suit where the jacket and trousers have some independence of usefulness gives you significantly more value from a single purchase. A mid navy or charcoal two piece in fine wool that’s well fitted is the closest thing men’s wardrobes have to a foundational piece and it’s one of those purchases where spending properly once is dramatically better than replacing something cheaper every few years.