I must first of all hold my hands up and say I have taught acoustic guitar in groups and on a one to one basis for over 30 years so my point of view may be coloured a bit by this backdrop.
There are some clear advantages to having acoustic guitar lessons with a specialist teacher in your locality.
Get good guitar habits from day one A guitar tutor will show you how to sit with you guitar in the right way.
You can been shown how to hold down the strings very precisely and where to strum the chords with your right hand.
By getting this set up correct from day one you will learn quicker because you will not have to adjust things later on because you have got into a bad playing position.
A guitar tutor gives immediate feedback When you use an online guitar tutor you will have a wealth of great learning materials before you.
You will probably work through the lessons in order and start to play guitar.
But if you do not have someone watching you, there might be things you understand wrongly.
You move on to the next lesson not realising your mistake and get confused when a later lesson contradicts what you thought you had been told earlier.
You will also learn what your strong points are from the eyes of an expert.
A Guitar teacher will set the pace for you How quickly you learn guitar is best decided by a teacher who knows what they are doing.
You may think you can just keep on working through your online lessons but how do you know when you should spend extra time on a particular chord or song? I am not against learning the acoustic guitar from online lessons, far from it, but they should be used in conjunction with the input of an expert.
You will learn guitar fast and well.