Automatic watches are a luxury toy for people who have a peculiar liking for them which defies all rational explanation. If you were one of these people, you would probably already know.
In short I believe that if you don't know you want a mechanical, you don't. This is contrary to what many knowledgable watch persons, especially enthusiasts, say and contrary to how it is in other areas (where it's easy to explain advantages and get people to instantly change their opinion).
For watches, it's not that clear mechanical is always an advantage, even though it attracts some of us quite a lot.
There used to be one clear reliability advantage for mechanicals when the battery in a quartz clock could start to get depleted and the watch quite suddenly starting to run 15 min or more late per day (and of course stopping suddenly) without any indication something was wrong. That clearly was unacceptable for some applications. Today, state of the art includes low battery indication.
Having the battery replaced by someone who doesn't know how to do it isn't a good thing as then water resistance can be gone (ask me, I know) and replacing it before its life is up doesn't feel economical. There are battery less solutions today so that doesn't have to be a disadvantage you have to live with either.
That said, I wouldn't ever recommend anyone who wants a mechanical watch not to get one. They do have advantages. Their obvious disadvantage compared to quartz watches, the lower inherent accuracy, doesn't have to be a major issue. It all depends on how you feel about it.