Lol you obviously know nothing about development, human resources and cost management. Apps dev could be done by employee working freelance, meaning that they get paid according to the time they work. You increase the workload? It costs you more money. It is also fairly possible that these apps development is fully outsourced (which is more and more common nowadays). Same in that case, the more work, the more it costs you.
And even if there are full time employee working on mobile apps, again, same. Either they have "free time" to dedicate to this (in that case it means that resources are poorly managed, since you shouldn't have employee paid sitting around doing nothing in your company). Either they are busy with other projects, you increase their workload, you have to pay them overtime...