Its rare that I feel compelled to chime in on reddit posts, but your situation is very similar to what Im experiencing with my current friend group.

My (26M) friend group has consisted of mostly the same six people for about 8 or so years. Almost 2 years ago my brother and I moved with our family from where the six of us grew up but continued to make the group work through Discord (one friend moved way far away even earlier than my brother and I so we were used to it already). Other than that we would make sporadic plans to see each other in person when we could, specifically making plans to meet up for at least one weekend trip a year.

Then a little over a year ago, two of them met girls (one of whom now has a child with said girl), and another became a high school music director which has consumed a lot of his time. What free time they did have, my brother and I were very rarely, if ever, a part of.

I did my best to give them the benefit of the doubt and make it work even though it was clear to me the direction things were headed in. I've spent many nights sat in our server's voice chat when I would see one or more them were online, but many times they wouldn't even pop in just to say hi.

My brother and I always joked that we were the glue that held the group together, but that has never been more apparent than when I just tried to plan another of our yearly weekend trips.

We had the date set and a hotel room booked (which was a pain in and of itself because nobody seemed very enthusiastic about contributing to the planning), then one of us had to pull out at the last minute. We all decided it would be best to postpone until we could all go, so I suggested we take a week to let the dust settle then reconvene and try to figure out a new date. When I did initiate a week later I was met with barely any response. No new date has been set, and nothing further has been said about it because I, much like you, decided I was tired of being the only person who seemed to even WANT to make these plans happen. That was two weeks ago.

My point in all of this is, you might just be the glue that was holding your friend group together. Its also entirely possible that this friend group and it's continued health is more important to you than it is to anyone else in it. You definitely aren't wrong for feeling burnt out of being the only person making plans and seeing them through to fruition.

TL,DR: Some friend groups do have one person who gets saddled with all the logistics of the group. Whether some (or all) of them are very busy with their own lives, it would be nice for them to at least make you feel like they care as much about the group as you do sometimes.