Would there be a problem with a large SharePoint List that breaks permission inheritance on List Level?

Question

Basically have a SharePoint List in SharePoint Online that has 100,000+ items. I want to change it so that permissions given to everyone (except admins) can only be Add items.

I know that there are performance issues when assigning unique permissions per item but how about just breaking permission inheritance on List Level?

Answer 1

Breaking a permission on list level would be ideal solution to go, it won't effect performance as security is trimmed at list level and it does not have to store permission for 100000+ items rather only for one entity.

Here is some metrics for your reference.

https://www.c-sharpcorner.com/UploadFile/40e97e/sharepoint-under-performance-of-unique-permissions/