GA4 Properties are still not linkable.
Having said that, the method for linking GA to GSC has changed and it's now referred to as an Association.
For GA, it must be done from within the GSC interface, not from within GA.
As of Feb 2021 you can now link GSC domain properties to GA (it's now recommended).
To get to the GSC Associations page:
https://search.google.com/search-console/settings/associations
You can associate your Google Analytics property with your Search
Console property to see Search Console data directly in Google
Analytics.
Any Search Console data exported from Search Console to your
associated Google Analytics property will be subject to the Google
Analytics terms of service. At the same time, any data exported from
your Google Analytics property to your associated Search Console
property will be subject to the Search Console terms of service.
Learn how to associate your Google Analytics property with your Search Console property.
When you associate a Search Console property with a Google Analytics
property, Search Console data is enabled for all reporting views
associated with that property by default. As a result, anybody with
access to that Google Analytics property or one of its views may be
able to see Search Console data for that site. For example, if a
Google Analytics administrator adds a user to property or view, that
user may be able to see Search Console data in Search Optimization
reports.
Google Analytics account administrators can move their Analytics
property from one Analytics account to another. Any associated Search
Console properties will maintain their association as part of the
move. After the move, any users of the new Analytics account will be
able to see data from the associated Search Console property without
anotification in Search Console.
Full documentation on GSC Associations can be found here:
https://support.google.com/webmasters/answer/9419894