Sure, you can increase the work, but you'll still be limited by bcrypt size
Otherwise, you could just MD5 hash stuff X times and be done with it
Sure, bcrypt today is very safe, but I wouldn't be surprised if attacks are found today (even if they rely only on bruteforce)
And let's not forget implementation issues that may happen in specific bcrypt libraries
Sure, you can increase the work, but you'll still be limited by bcrypt size
Otherwise, you could just MD5 hash stuff X times and be done with it
Sure, bcrypt today is very safe, but I wouldn't be surprised if attacks are found today (even if they rely only on bruteforce)
And let's not forget implementation issues that may happen in specific bcrypt libraries