Big -1
Safes are certainly not invincible, I have personally spent a lot of time getting into dozens of safes. When the potential reward is somebodies entire stash or a lot of drugs for example, there needs to be a certain level of security on the server for players. I have personally, on more than a dozen occasions, found houses unlocked and spent hours cracking the codes. Most times people have 1 safe code for all their safes, which is a terrible idea. Sometimes they will have 2 different safe codes across 5-8 safes. At the end of the day it is all up to you. If you are house-raiding and need them to open a safe, they cannot lie in /do about whether they know the code and all you have to do is NOT finish them if they are injured. It really isn't that difficult in the scenario of a house-raid.
The safes on ECRP only have 9999 different possible combo's, and after doing it so much it's not difficult to develop a strategy for cracking them. If the code is not in the first 50 basic 4-digit codes that I have previously encountered, then I have a strategy to go at it from there. You could hit it in the first 1000 codes you try, or you might get unlucky and have to try 9000 before you get it. This gives any player the chance to catch you in the act, or for any sort of roleplay to occur as-well. Any sort of item that could be added scriptly to crack safes would be unnecessary and make it a free for all. Having the patience to try a set of safes is something not many will do, as you can get a giant reward fast, or you could take 9000 codes just to get into a safe with a fishing rod or a burger. The 9999 codes system is already very clear cut. If you're smart you'll have a different code on all your safes to deter people from getting into them all at once.
I get the argument that there not being a safe-cracking item in-game is unrealistic, but if everything in the game was realistic, it wouldn't be a game nor would it be fun. There's a lot of things in the game that aren't realistic that we don't complain about because it would be terrible to play with.