Probably low chance of anything happening, especially from a camera.
I have a outdoor wifi AP that's fairly high (slightly above roof top), so I use one just in case. For the 15 bucks or so that a decent inline surge protector costs, I figured it was worth it. If I had to do 8+ cameras that weren't out in the open, I would probably skip them.
Seems to be the majority of people have had no problems with unshielded cable and without ethernet surge protectors. I think I'm going to go that route for simplicity and just use a spare PoE switch connected via fiber to my main switch to protect it.
I have a vacation house in a remote part of the world that I go to once a year for 4-5 weeks. The house has a power hook up but not much else. (There is a distant cellular tower, that provides Internet connectivity). I do not have neighbors or anybody who can come and reset any piece of equipment easily. Usually I have to pay a substantial amount of money to have the equipment serviced (other options include: getting myself there or just leaving the malfunctioning equipment until my next trip).
So far, I only had to pay once to have my camera fixed after what I think was a lightning strike.
Gather 'round, time for a story.
Every time I go there, I try to make it a little better. Every time I try to come up with a project or 5 on what to do while there. So for 2018, I wanted to install a few cameras so I could see what I am missing the other 11 months of the year. I gathered the following:
Asus RT-N65U flashed with the Padavan firmware
Some USB Cellular Modem
A Raspberry Pi 3B+ SOC
A TP-Link TL-SF1005P
A Reolink RLC-410 4MP Camera
A Reolink RLC-423 5MP PTZ Camera
Some CAT 5/6 cables
After getting the networking part done, I mounted the fixed camera right on the building, ran a ten foot cable to the switch and it worked! For the PTZ, I had a different plan. Since it can spin 360 degrees, I wanted to have a good vantage point, so I mounted it about 120 feet away and ran a regular CAT 6 cable to the switch. After plugging it in, it came online and all was dandy.
I came home and I was able to watch both cameras with the RTSP stream as well as the app. I was also able to wget JPGs. I wrote a script that would download those JPGs every 60 seconds, but only from dusk to dawn (thank you sunwait!), create a timelapse from those and upload it to YouTube for my viewing pleasure. It all worked flawlessly for almost two years until the early spring of 2020. One day I got a nagios alert that the whole thing was down. No biggie, I thought, it will come back up, probably there is no power (it happened before, but there was never a problem, since RPi's FS was in R/O mode). After about 18 hours the whole thing came back online sans the RLC-423. I tried checking the switch, arp, anything I could think of, multiple reboots, anything, no dice. I looked at the footage the script downloaded before the whole thing went cold. The sky was dark blue, purple even, there was a distinct giant shelf cloud all the way to the horizon. I knew what happened. I just had no idea what was the extent of the damage. I arranged for the service to go on-site and see what happened. A few days later first I got the nagios recovery message then a phone call that the service crew was all set - they ended up installing a POE injector and a POE splitter. It seems the lightning strike took out the camera's POE circuitry, but saved the equipment, on both ends, yay, lucky me! The camera still works, still the original device and while I have made two trips since then to the site (2020 and 2021) I have left both cameras alone. The project evolved but for stability I have only added a beefy UPS and two of Tupavco TP302s Ethernet surge protectors.
If you are in a certain situation, like me, a device like this can be invaluable, it can protect your equipment from an ESD.
So, it is a viable option. It has been working for me for a year or two (I am not sure when I installed it).
My camera installers (well, they're doing the retro cable runs) won't connect it to the grounding rod. They want a high voltage electrician to do that. I have to have one come over anyhow to install a ceiling fan in my wife's office and to replace some Z wave light switches that have gone bad.
So my ultimate decision was to run shielded cable to a Ubiquiti Ethernet Surge Protector for each cable run. That will be grounded by the electrician (to the grounding cable that runs through the unfinished basement most likely; it appears to go from electric meter to grounding rod on other side of basement).
From there, I'm powering it with a separate PoE switch.
My wife is really afraid that a voltage surge will damage our Synology RS1221+ NAS that she uses to store her photos on (professional photographer). It probably isn't likely, but I really don't want to have the conversation with her about why she lost all her client's photos or couldn't have access to them quickly because of a surge.
Finally got my cameras up. Used shielded cables with a surge protector that was grounded. From the surge protector I used unshielded. A little bit of a hassle to throw in the surge protector, but I feel more comfortable with the setup.