While it does take effort to put together an event, the amount of frustration/mental effect caused varies from person to person. I am someone who has frequently put together/helped put together events in FF, out of FF and in real life (specifically raves and having to deal with keeping DJs on schedule + hosting) that usually pull betweeen 100-200 people. I don't find them to be mentally draining at all to be honest, in fact it's quite fun and can be a really easy process if you know what you're doing.
One thing I want to point out is that people will show to do their jobs if the "management" treats them well and also provides a good incentive for doing said job. Those who want to just show up to enjoy the event will come if they simply enjoy the environment of your group/enjoy being a part of it. If people aren't showing up or are being lazy about it, that's most likely a sign that things aren't going well behind the scenes on "managements" end and you should probably look into why. If putting together events in general is causing too much stress on your end then maybe consider passing the job off to someone else. I can say from experience that allowing your members to also contribute ideas/help run things also leads to a higher desire to actually want to be there. For example, I actually put together an anniversary event plan for an FC on Aether that had around 400-500 members and it would be a series of activities going on throughout the day at each hour. Each event was ran by a member of the FC (both "management" and non) and they were allowed to do whatever they wanted, whether that's host a game, act out a play, play music, etc. When the event actually happened, I was told that they had a larger crowd than any of their previous years running their old event style & could see a noticable difference in people's excitement for the day. They're still using said event style today to my knowledge.
I also suggested on the first page that the content I had in mind would sync based on the number of people there, removing any actual # requirement of people needing to be online. One person could run it by themselves if they wanted to. It's just an extra activity to give FCs more to do than just provide a space for people to afk in the garden outside of FC held events.