For about 1.5 years on and off, we've been developing a system to rate tickets/requests sent to our team. We wrote it in Angular, and it turned into this feature-rich gorgeous application with custom-built graphical statistic tracking, in-app social networking capabilities, robust user profiles, etc.

Eventually, we no longer had time to work on it along with all the other applications we're developing. So we passed ownership of the app over to a couple of other developers on our team. You'd think that they'd just work off what we already built and keep the robust environment we created for them. But nope, instead of keeping everything we already built, they scrapped it all and started from scratch using React instead of Angular, and removed all of those robust features and turned the app into a shell of its former self. No more statistic tracking, no more social networking capabilities, no more fancy user profiles. Just a single page with a number representing how many "Good" tickets you've sent to us, and how many "Bad" tickets you've sent.

1.5 years and hundreds of hours worth of work, all gone and replaced with the most rudimentary basic React app ever.