I have this same problem with a guy I'm talking to.

He and I texted one night and then for almost 2 weeks nothing from him. I texted him here and there with full conversation(s) worth. He texted me Monday night and told me he was out of town for work. Never once told me so I felt like I was needy asf. Stopped texting again until today. I asked him on a date. He responded that he would know if he could this Thursday (asked him for a friday date.) I'm kinda at the point on that I don't really feel into him nor care to respond back. He use to press me all the time to be a constant texter. My guy does this alot and shares the same bad traits yours does. It annoyed me but now I'm kinda at the "eh w/e I'll just let him engage" point. Hate texting a few sentences and get back half a sentence.

I feel that pain man.