Some women have concerns about getting addicted to their vibrators - not in the sense of using them compulsively (masturbation addiction is a separate issue). They worry that they may become dependent on the vibrator for orgasms, and become unable to climax any other way.
A related vibrator fear is loss of sensation. Some women worry that using a vibrator regularly will cause their clitoris to become less sensitive over time, and eventually "ruin" it.
These fears are exaggerated but not entirely baseless. You can become habituated to any sort of stimulation if that's the only way you bring yourself to an orgasm. Your body and brain become accustomed to certain things, and it's hard to get them to switch gears and respond to other sensations and stimuli. That could make it harder to come during sex with a partner if you're not using sex toys.
It's also true that after you've gotten used to the strong stimulus of a vibrator, and have been using a vibrator frequently, manual or oral stimulation might not feel like that much to you, and it may seem that you've blown some nerve endings.
The good news is that all this is reversible. You and your vibrator just need to spend some time apart...and then maybe spend less time together while you switch off between different types of stimulation. Take a week or two off from masturbating altogether (if you can!). After a rest, your clit should feel wide awake, sensitive, and respond more easily to less stimuli, like your fingers.
It's easy to get used to the easy buzz and blast-off of a vibrator, and there's nothing wrong with that. But if you're concerned that you're getting too reliant on your battery-powered buddy, try mixing things up a little. It'll always be there in the drawer if you need it.