So how do you do say a DB mission that sends you to the Easternmost point on the map, you'll be there for five seconds then get called straight back to where you came from, if you honestly play like that then walking that distance would take a good few hours. How many missions have you completed since Nov?, like 6?.
I did start off just exploring by running everywhere but with all the back and forth missions it quickly stopped being feasible, I was spending the whole afternoon on the game and only completing one or two missions. I have multiple characters and playing like that it would take me years to finish all the quest lines, I have so many other top rated games still to play that I really don't want to be stuck on the same game for years because of some artificial limit I've put on how I play it.
Well, typically I have more than one quest going at the same time, so there's usually more than one objective to meet in an area. Also, I'm not trying to burn through the quests. I don't mind if it takes me a whole session, or even two, to walk from one end of the map to the other. I have various encounters along the way, typically stop in one or two dungeons or other locations that I want to explore, etc. I just happen to enjoy walking and taking in the sights and use the time to think about my character's objectives. And I will occasionally use the carriages if I think it fits my RP better. I've used them about seven or eight times. That's usually only when it seems like the quest is urgent and my character would want to get there as fast as possible.
Of course, I'm not saying anyone else has to enjoy playing this way. If you'd rather be doing other things, by all means don't let other people hold you back.
My main character had over three dozen completed quests last time I checked + countless side quests. It really doesn't take as long as people think, since you're rarely doing only one quest at a time. I usually advance/complete 2-4 quests in each location before moving on.