I am going to say that it is directly proportional to both your looks and what you are looking for out of a date. The largest issue most people face is finding the correct site to put their profile on for online dating, but a few google searches gets that one cleared up pretty easily. The next hurdle people often have is just based off of personal preferences. Most people look for fit, attractive people of the opposite gender with similar interests and an interesting or entertaining about them section. If you are overweight, underweight, have some form of physical asymmetry, or are otherwise unappealing in your photos (I.E. bad hygiene, poor lighting, multiple people in photo with no explanation or other photos, or just have nude posters hanging in the background) you will find online dating significantly more difficult. Likewise if you often find words to be unwieldy or are the type of person that makes things uncomfortable with your wordplay, you may have issues finding that special someone.
All of the other issues are pretty well a minimal issue in my opinion. If you don't like or can't do the online scene, there are still tons of places to go where you can meet people for the purposes of finding a potential date. Grocery Stores (these are number 1 pick up spots in my location), bars, cafes, parks, animal parks, hobbyist shops, and schools are all perfect examples of local places you can go to find people. In fact I would say that online communication and networking has actually made this easier as well. Instead of trying to get that girl's (or guy's) phone number at the grocery store that you just hit it off with it (AKA had a conversation lasting more than 1.5 minutes about something other than food), ask for their social media name or link (Facebook, Twitter, Instagram, etc...). It is usually easier information to attempt to receive than a phone number as most people have a ton of people they don't know or talk to on their social media pages. Once you have said connection, then try to reignite the conversation from earlier and see where it leads. Conversely apps like Skype and HeyTell are also easy to give out since they can easily block you if things don't work out and they end up not enjoying your conversational skills.
After a few conversations, see if they are interested in joining you and some friends when you guys go out somewhere. If so, try to get the phone number on that occasion and then move in for the date after a few phone chats. Many people have become so used to instant gratification that they may be over zealous when it comes to the approach in public, and for those people there are plenty of online dating apps that may make things easier or at least less complicated, but now we are back where we started.
The only places that I see really having been affected in a negative way are with the instant gratification issue I stated previously, and with people being more interested with their phones/tablets/portable gaming than they are in the date or even with paying attention to have the opportunities to actually converse with someone in public that might be a good match for you. I suppose that with the new generation of children growing up with online schools, tele-commute jobs, video over IP interviews and the like, they may not be as socially adept at talking to people in public, but that is easily remedied by just going out and doing it until you do have the experience (this is literally what I am working with my Godson on, as he is a youtube-a-holic).
The places where it has helped outside of the places previously mentioned are:
If you live in a remote area or have a bad reputation in your area, the online scene as well as instant video communication makes it tons easier to find a date without your past or location biting you in the rear.
If you are in a relationship and have to relocate or get deployed somewhere else (hell even if you just go on an extended vacation), you have the most intimate way of long distance communication that we have ever experienced on most of your devices (video chatting).
People can go online and find chat buddies to talk to and maybe get a phone number for, to help with interpersonal skills development for those either too afraid or unable to just walk up to someone and strike up a conversation.
I am sure the list could go on forever, just as I'm sure I missed some detriments as well, but I would almost guarantee that the pros far outweigh the cons on this subject.