Someone can be quite interested in the venture (and thus joined as a cofounder) but at the same time be pretty lazy, or busy on their other things. In this cas

Someone can be quite interested in the venture (and thus joined as a cofounder) but at the same time be pretty lazy, or busy on their other things. In this case, they are unlikely to "quit". They will show up in meetings and talk, but between meetings nothing much will be done.