Multiclassing of course gives a certain flexibility in how you create your character. Basically it gets a classbased system such as D&D5 closer to the flexibility of a skillbased system.
Just like skillbased systems such as for example Skyrim have made attempts to get closer to classbased systems with the introduction of feats, thus giving a skillbased system more of the properties of a classbased system, i.e. strong differences between characters. Not that TES is a good rulesystem and not that Skyrim is a good rulesystem either, but its better than its predecessors which only gave fixed bonuses for certain skill values.
