I am told to use "We are inviting you..." instead of "We invite you...". The reviewer mentions that this first option is progressive and more appropriate. In which cases do you use either one, for example, one case is inviting to a birthday party and the second case is inviting to a medical

I am told to use "We are inviting you..." instead of "We invite you...". The reviewer mentions that this first option is progressive and more appropriate. In which cases do you use either one, for example, one case is inviting to a birthday party and the second case is inviting to a medical treatment.