I believe what you may be looking for is custom client-side solutions using the SharePoint Framework (SPFx).
With the SharePoint Framework, you can create custom web-parts with whatever controls/functionality you need, or you can create “extensions”, which include field customizers which allow you more control over field customization than just the JSON formatting.
Here is the MS documentation on the overview of the SharePoint Framework.
Here is the overview of SPFx web parts.
Here is the overview of SPFx Extensions.