It's a simple opportunity cost calculation. The service is there, provides value. Creating a replacement is not realistic. Paying for another replacement gives

It's a simple opportunity cost calculation. The service is there, provides value. Creating a replacement is not realistic. Paying for another replacement gives you potential headaches from using a less popular service. So when choosing between not doing a thing or doing a thing with the risk of spof, it's often a reasonable choice to go with those services.