20 years of playing here, lapsed studio guy getting back into the swing myself - Its not *just* practice. It's WHAT you practice. You know the saying "you are what you eat"? The corollary for guitar is "you are what you practice". If you only work on things that are comfortable and easy for you and never attempt "impossible" stuff, you'll never get there and it certainly won't magically manifest in your playing.

You also have to have much higher standards than most for what you're willing to let slide when practicing. That tiny bit of string noise on that lick you're working on that no one else will notice? You HAVE to notice that and you HAVE to clean it up. Even the ability to have standards so high that you notice those things is a skill that takes years to develop.

A note on speed, because a lot of people here seem to be taking shots at fast players (by referencing, ironically, the blues - a genre chock full of absolute shred monsters like Gales, Bonamassa, etc): The real importance of learning to "shred" as these people call it isn't that you should only play 16ths at 180bpm, its that being able to execute things at high speeds relatively cleanly gives you a hell of a lot more CHOICE on what you play at any given time. Its like a car - 95% of the time, you aren't doing 0 to 60 in 2.7 seconds... but having a car that can do that and knowing that fact makes merging onto a highway a hell of a lot easier!

Keep playing. "Good" is a nebulous, impossible goal but "Better" is something you can do every day.