Always the one planning? Say it out loud. People can’t fix a lopsided thing they haven’t noticed.

Most imbalance is not deliberate, it is unexamined. Whoever always organises gets a reputation for liking it, and everybody else drifts into waiting because the plan keeps appearing, and none of them have run the calculation you have been running for a year. Quietly resenting it will not surface the information. They genuinely do not know.

Say it plainly once, without the list of grievances: tell them you have planned the last several and ask somebody else to take the next one. Then actually leave the gap, even if the week goes unplanned. People step in when the vacancy is real.