4 answers
Adding to the other comments, the usual culprit for this is that the List View needs to be filtered by Record Type. In case it's not clear from the other comments, make sure your List View is filtered to only one Record Type (you can apply other additional filters as needed) and make sure the fields you want to be able to edit are visible and editable on the relevant Page Layouts. Additionally, make sure the Mass Edit from Lists permission is enabled for the relevant Profile(s). Note that there are some additional considerations if you use Person Accounts. Hope that helps! https://help.salesforce.com/articleView?id=000323035&type=1&mode=1
