No. Whiteboard is not essential. It is NOT inseparable form teamwork. That is just one possible tool. Maybe the only way you know perhaps? If you must use it because that's the only way you know for collaboration then look around for better ones than the ones you know. There are physical ones connected to net (practically a huge touchscreen on legs), or there is this novel concept called tablets, those usually come with online connection too, spectacular, eh?! Alternatively you may use the traditional whiteboards to brainstorm about remote whiteboards. ; )