I spent hours waiting for a trial group in Craglorn (where most of the trial groups form). It was all for naught. The one time we somehow managed to scrape a group together, it ultimately disbanded because there were no tanks. Why isn't there a Trial Finder? The way it is now is inefficient and time consuming. The massive benefit to having a Trial Finder mechanic isn't only to put groups together, it's also to do other things, like questing, while waiting for a group to be formed. The way it is now, I have to loiter in Craglorn, with no content to do, waiting for somebody to put a group together in zone chat. Having to wait hours and hoping for groups to form is not fun, nor is it content.
Guilds are not the answer either, even trial-specific or heavy guilds. I'm in a general guild and they're running (or vocalized they were running) two different trials neither of which I wanted to run because it didn't have the gear I wanted. This is why a Trial Finder mechanic is necessary. It puts like-intentioned people together and allows you to actually play content while waiting.