Agreed with all of the above.I would absolutely continue. There is no way you can duplicate the distractions that a group class just naturally involves, let alone those a good instructor can add. Just having other people in the room means they can toss treats when you are heeling, play ball when you are heeling....
Plus, it's definitely a case of 'you don't know what you don't know' and a good instructor can instantly give small hints and tips the first sign of a problem, that you can use and adjust, and then there never IS a real problem because you prevented it from being learned 'wrong' and having to later come up with a much more problemic fix.
I also have made friends over the years in dog classes to hear about upcoming dog events. That's how I got into both therapy dog work and agility. I still have friends that I meet for dog walks/hikes/barbeques that we know each others dogs and can all attend. REally important is THEY can take my dogs if I go out of town with no worries, and I can take THEIR dogs if they have to leave. Huge comfort to know my dogs are in a safe home having a blast when I have to leave them (I have never had to pay and use a commercial kennel)
So if your instructor is awful, I'd look for new classes. And if you get bored with obedience, I'd also look for other classes in the area (herding, rally, flyball, tracking, AGILITY......) so you can keep up training/socialization/dog stuff.
Plus you might look into whether your club has an advanced group, agility class, or something to that effect. Ours does but in order to be in them you have to graduate novice training.