Yes it's safe to drive a car with a bad or clogged fuel injector.
The only thing that will happen when you have a bad or clogged fuel injector is that your engine can lose power, may not accelerate properly, may stall, may miss under load etc.
But as long as your other fuel injectors are injecting gasoline into the engine the car will or should still run so it's not dangerous to drive the car with bad or clogged fuel injectors.
However your fuel mileage will suffer and your car will use more gasoline when the fuel injector is bad and it won't run properly so it's best to replace the fuel injector or if it's clogged have it cleaned if possible.
Fuel injector cleaning can be worth it if you're having issues with your fuel injectors.
Fuel Injectors need to be cleaned so that they spray out the fuel properly and when the engine doesn't get enough proper fuel spray then the engine may misfire, surge, stall, lose power etc.
So if you're noticing those issues then you should probably have your fuel injectors cleaned.
You can also just pour a bottle of fuel injector cleaner into your gas tank when you fill up your gas tank and then it should help clean partially clogged fuel injectors.
The cost of having your fuel injectors cleaned professionally ranges from $50.00 to $80.00 and can sometimes cost as much as $100.00 to $200.00 depending on how many fuel injectors you have and how hard it is to get to the fuel injectors.
Some fuel injectors are easy to get too and remove to clean and some fuel injectors may be harder to get too and remove because they may be hidden under other stuff that needs removed.
But it should not cost any more than $200.00 to have your fuel injectors cleaned.
If you're experiencing poor fuel mileage or the engine is misfiring and you've replaced ignition coils then it could be the fuel injectors causing the issue.
Having the fuel injectors cleaned can be worth it and sometimes it's just as cheap and better to have your fuel injectors replaced if they are really bad or clogged.