It has been a long road. Eleven long years. WordPress will finally allow end-users to update an installed plugin or theme by uploading a ZIP file. After over a decade, most people who had hoped to see this day have likely moved on. However, for those of us still waiting for this long sought after feature, it will land in WordPress 5.5.
A little patience never hurt anyone. Over the years, we have seen plugins crop up to handle this missing feature. There has been a clear and present need for it. Easy Theme and Plugin Upgrades by Chris Jean