I was wondering how you guys saw leadership during your games and if it positively improved your campaigns. I'm a DM and a lack of leadership from the players is a common problem I see.

I see it as more of a maturity issue, really. By leadership I assume you mean one person taking charge of a particular scene, or being the focal point in the party for the decision making. And sure, it is usually important to have someone in charge, kinda. But in order for that to happen, the other people must be willing to offer their input and then defer to that leader. Deferring one's command is a difficult thing to learn to do. It requires a great deal of maturity to be able to recognize when another character is having "their moment" and to just sit back and allow the space for that moment to happen. It's like if everyone tries to go through a doorway at the same time, no one will get through. In order for anything to get done, some people have to be willing to take a step back and create the space necessary for everyone to get through the door. 

The problem is, I have no idea how to teach that kind of player maturity. Heck, I don't even know if it can be learned, or if it's just something that each person has to develop on their own. I mean, every party has one or a few people who always want to be in the spotlight, but it is equally important to have people who naturally enjoy being in support roles. 

I disagree that characters with dump charisma can't lead the party.

Charisma is great for making friends and being popular. Popularity may position you to a place of leadership, but it doesn't have to. Most people have met that person who you are glad to see at party, but you'd never trust them with any kind of meaningful task.  Likewise uncharismatic people can be successful leaders based on other characteristics which make them competent and hence people follow them because their lives literally depend on the competency of the leader. 

It is very difficult for a player's personality to not reflect to some extent through their character. And that's ok. 

If a party doesn't have a leader, that isn't necessarily a terrible thing. Actually as the GM this can be great. You can write in an NPC and direct them where to go and what to do if you have a bunch of followers and this can really cut back your prep work because you can probably funnel them anywhere you want to go.

Hmm... My party seems to mostly do things by committee... Given how I detest committees in real life I'm surprised that it works, but so far it has.

In my experience, the healthiest form of group governing is by group consensus as BioWizard alluded. I will say that having a character(s) who wants to be the "face" can be very useful if only to convey the party's wishes to NPCs with the weight of decent social stats behind them (or whatever). The issue then falls to making sure Mr/Mrs Face doesn't hog all the screen time in inter and outer party discussion as Lyxen suggested.

Quote from Lyxen >>

One of the main problems is not to mix leadership from the player and that from the character. While ooc discussion, there is not much that you can do about the first one, apart from making some players aware (it took me a long time to realise that about myself, and I have to constantly remind myself of it) that they are taking too much space in discussions and decision making. Fortunately, with the player base in our groups, we have some discrete players but also quite a few with natural leadership, so it's not usually too much of an issue when the problem above is taken care of.

After that, it's really important to empower any player who wants to have a "leader-type" character by making sure that this and the charisma of the character (and associated skills) are being used, rather than just the roleplaying from loudmouths. Again, once you are aware of it, it's not too much of a problem, although we do have to remind some of our players now and then that they dumped their charisma, and they can't lead at all.

That being said, I liked the leadership feat of previous editions. I don't miss it too much in 5e, and it led to some complications, but it was a nice touch.

And in AD&D leadership was basically a class feature.

I have one player in my group who usually takes the lead on everything: he’s not pushy but he role plays the most and takes it fairly seriously. He also tends to keep the story going forward and make final decisions for the party. One campaign, he tried playing a laid back “follower” character and the party ended up totally directionless, effectively killing the campaign (it was a sandbox)! So I think it’s important to have at least one player who’s a leader, just to give the group direction and keep the game moving.

Also, Charisma isn’t a required stat to lead the party. A low Charisma leader might not speak for the party in social interactions, but they might decide who to talk to and what the goal is, then point the party face in the right direction. Leadership in D&D is more about making decisions and moving the party than about talking to NPCs. My halfling paladin, Milton, once had amazing Charisma and tended to be the party face, but his low intelligence and wisdom meant he wasn’t the real one in charge. That was the less likable but much smarter dwarf cleric!

I have a player that leads discussion but doesn't force opinion. They come to a consensus and the group decides. It works fairly well as some in the group are soft spoken but their opinions are respected.

I am little confused about the question. But in my groups I have two "leaders". One is the pc who most likely handle the situation in game. Ex. Tim Thief handles the pawn shop deal while Peter Paladin handles the run ins with the police. The second is a party caller. That is Bob. He decides with input from the group which direction the group takes. EX Left at the T-section. No we will go to the church first then go to tavern.  I started the party caller bit decades ago after I sat back and watch the group debate for two hours which direction to go in an Alice in Wonderland module.