There's a huge difference between an online agent and a hybrid agent. Some online agents won't come out and value your home they'll just do an email val without even coming out. A hybrid agent has all the benefits of the online but with real local experienced people on the ground.
I work for a hybrid so I am pretty biased but think it's great. I'm self employed so my motivation to sell your home is referrals and reviews to build my local business. Having a for sale sign up for months on end doesn't do me any favours, I want to see a sold sign up on the street and I want you to be telling all of your friends and family what a great experience you've had with me, in hope that they might use me in the future.
The main benefit is the accessibility for you and your potential buyers. The highest traffic on RM and Zoopla is between 6&10pm weekdays when the traditional agents are shut so your buyers will have to wait until the next day to try and book, or if they see something on a Saturday afternoon will have to wait until the Monday - with online agents they can see something they like and book in a viewing within minutes!
You can view and amend your advert 24/7 and look direct at your performance reports and viewings history. Your not relying on an agent feeding you info which they may tailor to suit them. Same with offers, the agent can't put the one that suits them in the best light (for example if one buyer is doing their mortgage through the office and they will get extra commission from that).
having worked in the high street for years I feel a lot more productive being able to work when my customers and buyers need and want me to and not being restricted by office hours or having to stay in the office when everyone else is out on appointments. A lot of my customers work so I usually catch up with them after 7 if that's what they need, it works for them and I'm more than happy doing it.
With any business there will be agents in the high street, online or within a hybrid who are awful. EAs have a terrible rep because there are 'fly boys' out there but I think if you get a few out to value your home and start building a rapport you'll find one you like ( I hope!)