How do you deal with friends who never come to your stuff (parties, dinners, get togethers)?

My husband's best friend from college (and his wife and their 3 yo daughter) lives near us and we were all pretty close before I had M. We would have dinner at their house once a month or so. After I had M, things changed a lot bc we couldn't just go to their house all the time, since we both had kids to deal with now. Since then, I've noticed they don't come to basically anything we invite them to, but we're always expected to come to their things.

We host an annual cookie party, they've declined two years in a row, we've invited them out to dinner, always a decline or a vague "yeah maybe! We'll let you know". They came to our super bowl party for like 20 minutes and then had to leave for naptime, declined my baby shower.. Really the last party I feel remember them coming to and actually being at was my husband's 30th, which we over 3 years ago. Now, M's first birthday party is tomorrow and they RSVP'ed yes. I just got a text saying their daughter has been sick and still have a cough so they won't be coming. I'm sure it's true, but I'm having a hard time believing this stuff always only comes up when we're hosting something or we have plans with them. Meanwhile, we've attended most of their things over the years (2 annual parties each year and 3 birthday parties, we've gone to all). I've also made the effort to attend events that she plans with a group of moms (moms night out type stuff).

At this point, I'm really frustrated and want to just stop inviting them. My husband still talks to his friend often but I don't feel like they're making an effort to actually be friends with us. And I don't like feeling like she only wants to do things with us or see us when she plans it. So any and all advice is much appreciated.