
Dear @Shawn Chen
Hope you a good day.
Currently SharePoint recommends a maximum of 2,000 lists and libraries per site, and 2,000 subsites per site. These have been long standing limits for SharePoint but have not been formally enforced.
There have been cases where some sites exceeded these limits, resulting in poor site performance and low-quality viewing experience. One of the most impacted areas is the API performance that degrades significantly when users access data on the sites that exceed their recommended limits.
Therefore, to ensure site performance and help customers have the best possible experience, Microsoft will implement a safeguard to prevent customers from exceeding these limits. The enforcement of the limits will start in early November and will be completely enforced by late December. When a site reaches these limits, users will see the following message on SharePoint web:
For more information, you could refer to:
https://petri.com/m365-changelog-site-limits-for-sharepoint-lists-libraries-and-subsites/
Note: Microsoft is providing this information as a convenience to you. The sites are not controlled by Microsoft. Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please make sure that you completely understand the risk before retrieving any suggestions from the above link.
Thank you for your time.
Yours faithfully,
Yi Lu
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