You have shot wedding and cosplay..
Speaking from experience, and I assume you are talking about Malay weddings, I would definitely not recommend any lens above 70mm.
You need to know what and how much of a focal length you need in your work. 70mm at void deck wedding with crowd is simply unusable. AT ALL. Therefore, your option for a 70-200 is out.
This applies to your cosplay as well. How many cosplay event have you attended? Have you been able to work your equipments well with such a big crowd? With crowds around you, you will only need a focal length of 40mm and less. I have yet to see anyone using a white L glass at any cosplay event. I tried using mine, but the working distance between me and my subject at crowd place is way too much.
What you currently have is enough for your needs. Like what others have said, what is your motive in taking pictures? Why decide to move to another genre?
I do sports and events and I have been using 70-200 F2.8L IS II with a 7D. Sports genre would require high end equipment, which is expensive. I find it unreasonable if I were to recommend you this or if you were to follow my foot steps. It always depend on your budget and your needs. Some genre may in need high end big glass and body, some may not.
Even my Canon EFS 18-200 f3.5-f5.6 IS is still my walkaround lens daily. I even use it for landscape.