Well, I would say there are pros and cons to both, and some classes get more out of mulit-classing than others.
Take the Eldritch Knight vs the Fighter/Wizard for example. Multi-classing gets you a Wizard that has some fighter armor/proficiencies, but the Eldritch Knight gives you an ability called War Magic that lets you take an attack as a bonus action if you used a cantrip as your main action. This makes your Wizard and Fighter abilities more seamless imo.
There are other combos that are almost always superior to their single class counterparts. Take the Paladin/Warlock combo. Paladins can use spell slots to give their attacks an extra boost of divine energy. This is called Smite. Well, normally, a Paladin would need to long rest before spell slots come back...but Warlocks get a few spell slots back at short rest. So, a Paladin/Warlock would get more Smites per day than a normal Paladin ever would.
My very first 5e character was a Level 2 Warlock/ Level X Bard. With two levels of Warlock I got two spell slots that came back every short rest along with the ability to cast Disguise Self at will...And so many other classes benefit from small dips like this.
Last edited by Gmazca; 02/03/20 07:11 PM.