Wireless work fine 99.99% of the time. Your system can be compromised with the right equipment. That is how thieves are able to hi-jack car key codes and drive off in expensive cars in minutes. As I have said, insurance companies will not accept a wireless alarm system or camera system if they stipulate you must have one on condition to have the insurance. Government agencies will not use wireless systems.
Your camera system and alarm system can only give you early warning. There are many more things you can do for your own protection. How easy is it these days for a miscreant to ring a door bell and push his/their way in. Or, to bump a key and walk right into your home? I am even considering interior metal gates on a basement door and side garage door. All it will take is a log to be used as a battering ram to break the door.
I was talking about reliability, which is the the relative strength of the signal. That's different than security, which is the network's ability to protect against unwanted intrusion. You can have a reliable i.e. strong signal network that is insecure. You can also have a secure network that has unreliable i.e poor signal quality.
Any system including wired can be compromised with enough effort. Someone could theoretically get under a camera and plug in a laptop to the Ethernet jack. Then they'd could have access to your enitre local network. There would be a few challenges in doing that though including not being seen by any cameras, setting up a ladder, and removing the camera from the wall.
Any wired or wireless system can be hardened with enough effort like upgrading the firmware or segregating your cameras from the rest of the network. This is more advanced than what the OP is looking for so I'll leave it to him to do the research.
I'll have to take your word for it that some insurance companies won't accept a wireless security system. Same thing with government agencies not using them. On the other hand, we won't know what the OP's insurance company policies about security systems and he's not a government agency. He's just looking to setup a camera in front of his garage.
Of course there are many things to protect your home like installing stronger door locks, garage opener, dead bolts, door frames, metal doors, security film on windows, bars on the windows, metal box for key fobs, etc. The issues with security film or bars is that you need to be able to escape the house in an emergency.
Anyone can certainly ring your bell in the middle of the night. If you're concerned about that threat, then use a doorbell or face height camera that has an intercom system. Use the system to check on who's at the door, ask them to leave or just don't answer.
