For years I've wondered why WordPress never integrated into the Dashboard > Updates area, the following alert when upgrading themes and plugins:
"Are you sure to wish to upgrade? Upgrading may overwrite any customizations you've made. Please makes a backup if you're unsure. Continue anyway?"
And then they must click "OK" to proceed. There is a similar warning when there are WP updates available, but not for themes and plugins.
Although among many of us this is common knowledge, that there are best practices like using a child theme and so on, this is advanced and unknown to the majority of people that use WordPress.
It's the most common issue I've seen over the past five years, people killing/undoing all their customizations or worse getting the white screen of death with plugin upgrades. People have absolutely no idea that they are overwriting their files.
People will never learn and it's a simple solution. This has been well needed for years and is an absolute must to be added to WordPress, where there are warnings and fail-safes for so much else, there is nothing for the most obviously needed and problematic areas of WordPress.