By "early" did you mean early January before the IRS opens for the year in late January, did you mean just early in general after the IRS opens? As @SteamTrain mentioned, filing in early January before the IRS opens can create problems for some early filers and can delay processing or require an amended return which can take weeks to process
As for "any" benefit, other than "potentially" receiving a refund sooner (if all goes well), here's another benefit:
If one is worried about ID theft, then one benefit of efiling soon after the IRS opens would be to prevent someone else from efiling a return (or at least making it more difficult for them.) While that may help to some extent, the best way to protect one's tax return is to start using an IP PIN (6-digit Identity Protection PIN) each year. The IRS does allow people to opt-in to that program voluntarily. Once opted-in, you have to retrieve a new one every January from your online IRS account. Those who voluntarily opt in can typically also opt out, using the IRS online account.
NOTE: People who file early and have the Earned Income Credit (EIC) or the ACTC (Additional Child Tax Credit) can still have a delay in their processing. By law (PATH Act), the IRS cannot start to release those refunds for those with those credits until February 16. So many with those credits will not receive their refunds until late February/early March.
