Hi Filip,
Thanks so much for reaching out!
This is done in order to easily know that things are working properly in that department. It should not cause performance issues on your site however.
If you are concerned about performance issues, please have a look at our Performance Considerations and see if there is anything you can adjust in order to help your site run better:
https://theeventscalendar.com/knowledgebase/performance-considerations/
After that, you may be interested in caching, so take a look at this article: https://theeventscalendar.com/knowledgebase/caching-basics/
In addition, you can check out some of the solutions provided in this forum post:
https://theeventscalendar.com/support/forums/topic/decreasing-loading-time-for-big-amount-of-events/
I would also recommend looking into some of the plugins in this blog post, as they may be able to help you pinpoint where site slowness may be occurring:
https://theeventscalendar.com/favorite-developer-plugins/
Let me know how it goes and if you need any further assistance on this topic!
Thanks,
Jaime