Wildcard certs are a security ops nightmare. You really don't want to throw the private key for that around to every small project, and you need some good, automated way of rolling them across multiple services. Doable, but if you can avoid this, it's a better to avoid.

This 100x - in just about any organisation of any size, if you use a single wildcard cert for all internal services, then it's inevitable that the private key will end up in the hands of an employee that shouldn't have it.