The problem is that some people don't have just one thing they are doing at a time: they have long-term projects that overlap in scope. I am a teacher at a University, where I am teaching multiple classes and helping multiple students. I am also an elected government official, where I am sitting on multiple committees and making decisions on multiple topics. I am also a software developer working on multiple projects and doing research into multiple algorithms. I am also a human being having fun in multiple ways and talking to multiple other people. Do you really insist that I finish, shut down, and serialize the state of every single task I am working on in order to work on some other task? That is probably the least efficient process I think you could come up with; every single sub-task I have has its own working area, and each of those involves maybe 12 tabs... so the result is many hundreds of tabs. If you only own one table, which you have to share between work as diverse as soldering and cooking, I highly recommend trying out a life with two tables for a while, as you might be shocked at how much more efficient life becomes when you don't have to pack up everything you are doing every time you get hungry. What makes a computer interesting is when you then realize you have an effectively infinite number of tables.