There is currently a 255 character restriction on Hyperlink fields. This restriction impedes ability to save Urls that might include hash values are long query strings. Some examples where this is really common are links to SSRS reports (with parameters) and Search urls that contain refinements.

In List multinline text field can store only 63,999 characters only. but on other hand ,in library multiline text field can store un-limited data. please make this functionality for list as well.

SharePoint Online. We really need to set some restrictions of file types that user can upload to a document library.
For example, to deny upload file with extension .bmp and .tiff.

Add a photowebpart that shows the content of a picture library in thumbnails. when you click a thumbnail, a popup will appear with the photo in a "normal size" (as available in _w hidden folder) and than you can browse the photos with next/previous buttons, with an option To show the picture in original size.

Allow to display filename attribute instead of title in Highlighted content webpart

Provide an editable field for publish date of pages and news articles. As we migrate content from another platform it's important to maintain existing "published" dates

Introduce Accordions & Tabs (In-page) web parts | More Table Functionality

Accordions help users see only the content they need. Accordions expand and collapse sections of content with a title.

Horizontal & Vertical Tabs (In-page)
Tabs are perfect for single page web applications, or for web pages capable of displaying different subjects.

Tables are very limited. You can't even merge a cell? Enough said.

Please provide option to customize email templates used to send notifications out of SharePoint online like "Send by Email" feature on modern UI pages, sharing notifications to other users. Most organizations do not allow users to install mobile apps. Providing information that is not approved will confuse the users and require constant training.

Content types are an essential part of SharePoint. One issue that has been around since SharePoint 2007 is the absence of an overview of all applied content types. Why is this important? Try to delete a content type and you get the message it's still in use. Good luck finding out where. This is very frustrating and time consuming. That's why I vote for an overview where you can see where the content types are applied.

My users would like the ability to publish a modern page on a given time. Now it is only possible to publish a page directly. Make it possible to publish a modern page on time the user (optionally) enters in a datetime field.

Categorize and filter news articles on new publishing site
Ability to select category (or multiple) for a news article when you create it. Plus the ability to filter the news widget by category.
Exactly like you can for events. Plus the ability to select multiple categories if you choose.

It should be feasible to sync updates from Excel to SharePoint Online list. We can import the Excel sheet to a SharePoint Online list or export a SharePoint list to Excel file. However, the sync between them is one-way.

Changes made in the SharePoint list can be written to Excel, but any changes that we make in Excel won't written to SharePoint list automatically.

Option to remove "See all" link from List web part, when you don't want users to access the underlying list

Back in September, we have used below columns to extract picture/image metadata w.r.t location in SharePoint Online:

wicSystemGPSLatitude
wicSystemGPSLongitude

It worked brilliantly. But unfortunately the functionality doesn't seem to work anymore.

Other metadata such as date taken has also been removed. This is causing extreme headache for customers who relied on this data.

PLEASE BRING THIS BACK!!!

It would be nice to have the option to place a web part on a modern page and add HTML to it. We don't always want to jump to SPFx for something simple. It would help add some flexibility to the modern pages.

Security trim the hub site's top menu bar

Office 365 Connectors within SharePoint are only available for use within group-connected SharePoint team sites, according to https://support.office.com/en-ie/article/use-the-connector-web-part-db0756aa-f78f-4b74-8b19-be5dca0420e1.

Please add support for using Office 365 Connectors also in Communication Sites. For example, I would like to display data from outside by using an RSS Feed connector on a Communication Site page.