Wedding Favors at Ceremony

The ceremony is not the time or place IMO. Favors are not necessary at all, but if you are intent on having them the reception itself is how and where you thank the guests for coming.

Favors are always optional and frequently left behind but the ceremony is not the appropriate place for them. Give them out at the reception or skip them entirely.

As a guest, I wouldn’t mind receiving a favor at the ceremony. Especially if the reception is being held at another location. This would make it easy for them to take the favor to their car right after the ceremony.
There are lots of examples of this online, and it actually looks really cute!

I think it sounds fine, but you may want to warn people to check their seats first. This is especially important if the favor is something like chocolate or delicate glass.

Sidenote: I think one of the reasons favors get left behind is because they are given at the reception, where people are celebrating, eating, dancing, and enjoying cocktails- it’s easy to lose track of them, or just forget them completely by the end of the night. If they are given at the ceremony, it will likely eliminate (or at least cut down drastically) the amount of favors forgotten/left behind.

I don't see an issue with it. Not sure why others do.