Using a JSON snippet, it is possible to show or hide a field in a form for an item in a modern list based on the value of another form field. This capability does not currently work if referencing the value of a Lookup field. Please enable this ability so that the value of a Lookup field can be used to show or hide form fields.

References:
https://docs.microsoft.com/en-us/sharepoint/dev/declarative-customization/list-form-conditional-show-hide

https://github.com/SharePoint/sp-dev-docs/issues/6249

As we are using lists for tracking the status of various tasks and items, we're using a column field to indicate which items are completed. As our list grows, we're unable to archive completed tasks which are ultimately making our list cumbersome and unwieldy to use.

I would like the ability to archive a List item so it can be hidden from the List but can be still be viewed if needed.

When you create a view in modern picture libraries and include the thumbnail image, all of the columns are hidden. Need to be able to include the picture plus columns in a view like you can in classic.

By allowing conditional formulas to be applied to Choice columns, we can have more control on how these specific columns respond and interact with sibling columns.

With the flexibility of uploading attachments to any given list, it would help attachments to visually stick out if we could some how set list setting options on attachments to display at thumbnails, for jpgs, pngs, pdfs, etc...

Allow users to add CSS formatting options to the form body, for the purpose of adding more flexibility to the look and feel of our lists. At the moment there is not way to do this on the displayname, or field items, all within sections.

To highlight the items which are added comment, and quick overview for the all list, I suggest that comment icon should be able to be shown not only with the title column, but also other items which are created by SharePoint user.

You will find more detail as below, which I have asked on Microsoft Community.

https://answers.microsoft.com/en-us/msoffice/forum/msofficesharepoint-msowin10-mso_o365b/comment-icon-on-sharepoint-lists-item/930e7fb9-a687-44ac-b253-7e8ba6a902d8?messageId=1c49eac1-b8f1-4365-b026-63c3d1bb4281

Please make it possible to discover the RSS feed for lists. Currently it is only accessible to list administrators who must in turn manually publish it. It needs to be discoverable without administrator action.

Contact List that can be used for Outlook Distribution List and link to SharePoint Contact List containing Outlook Users that we can keep up to date with outlook changes especially in Distribution List memberships

Reviving this previous suggestion.

https://sharepoint.uservoice.com/forums/601165-suggestion-archive/suggestions/19788682-add-networkdays-function-for-calculated-columns

Is there work being done to apply list view security? we can use modern SharePoint page to display the list web part and hide the menu but we lose the sticky column feature and UI enhancements.

when viewing the list directly, want to provide instructions and static text above the list title and maybe a link to a company process or policy. This would be static and always visible when viewing the list.

Ability to edit data type, even delete the 'Tittle' column when creating new blank list as we may not need this column in some cases. Moreover, because of it, we have to change our template to add in List just because we have extra required column, which is very inconvenient for work purpose.

The InfoPath and PowerApps attachment controls currently allows the selecting and uploading of only one file at a time from the file browser window. Users are requesting the ability to select and upload multiple files simultaneously by pressing the Ctrl key and selecting the files.

Right now it can be difficult to engineer a valid query to filter on a date range for lists above list view threshold. Please allow the ability to specify a query between dates. For example if looking for items with a date within a given month in 2020 the server must first query all records after the start of the month or before the end of the specified month. This immediately hits the threshold even if the date field is indexed.

If a list column has custom JSON formatting, and the column is hidden in the list view, the JSON formatting is not applied when the item is viewed in the Open item panel (i.e. when double-clicking on the item).
The column is formatted correctly in the Properties panel and in the DispForm.aspx page.

Please add the JSON formatting to the Open item panel even if the column is hidden in the list view.

If a list column has custom JSON formatting, and the column is hidden in the list view, the JSON formatting is not applied when the item is viewed in the Open item panel (i.e. when double-clicking on the item).
The column is formatted correctly in the Properties panel and in the DispForm.aspx page.

Please add the JSON formatting to the Open item panel even if the column is hidden in the list view.

List forms can be configured to group fields into sections using the Configure layout option. Columns/fields can also be hidden dynamically using conditional formulas.
If all the fields in a section are hidden because of the conditional formulas, the section is still displayed (section heading, no fields, with section separator).

Please add the option to hide the section if all the fields in the section are dynamically hidden.