Loosing a few pixels or missing some object updates won't be noticable in high fps games, but where correctness and completeness of data is needed, UDP based applications end up implementing TCP features in application layer.
These application layer implementations can be more performant (low latency and/or high throughput) with UDP, utilizing the special cases, than TCP, which needs to provide generic facilities to every application running on the same host. And then it becomes a question of available resources vs benefits.
Example: DNS started as UDP and later used TCP when expectations on correctness grew.
That said, We have high capacity and high quality backbones that UDP looks right choice for many cases, and should be used where it makes sense.