CCTV is "closed circuit" and by nature stays off wifi and internet, but it's fully wired and a much more expensive approach
If you're going to get a "consumer-grade" one, then you'll need WiFi switched on 24/7 - thats how they work and communicate between devices.
Other brands to Euphy; Ring, Arlo, Google nest
Couple other things to think about:
- How many people are going to use it? From what I understand Euphy only lets one person logged in at a time to the app / device. That means only one phone gets notifications instead of the everyone in the household. I dont have direct experience with Euphy so could be wrong, but thought thats what I read when originally looking into it - someone who owns one can correct me if wrong
- Wired or battery; Wired offers some benefits, depending on device. On my Ring front camera for example because it's wired it continually records 6 seconds and then when it detects motion, it will stick the preceding 6 seconds onto the footage so you get the full view of the person / action. My back garden camera is battery operated and to save battery, it will only "wake" and record when it detects motion. That means you often pick up the action a bit delayed. I used to have something like that on the front of the house, and would regularly have a video of the postman walking away from the house, but not coming up to it because he was in and out in <5 seconds, so you'd miss people's faces if that was the case. That's not a problem now.
They're all relatively equal with different strengths and weaknesses to be honest. If it's purely for deterrence and things like the video front-loading I mentioned above dont matter, just go for whatever one feels best