Oh, for sure. It is funny b/c on my day job I review construction drawings and shelter / building drawings for telecom locations and cable chases, conduit, etc is always a point of conversation. Pivot to normal life and my disconnect is like "oh okay, let's discuss one of the other 10,000 things we need to consider."
All camera's should really be PoE (power over ethernet) from here on out, so not sure if conduit is really worth the extra cost (unless there is no attic access and/or there are a bunch of wall/floor beams in the way). If you want the electrician to run the Cat-6, then plan for female connections on each end, as I've read male Cat-6 connections can be tricky and introduce hard to diagnose gremlins in security system feeds, even for professionals. On the security camera enthusiast site linked below, they generally recommend that all male connectors be attached to the wire under factory conditions from a reputable company. So you use patch cable to bridge the gap from the house wire female to the camera female.
Otherwise, if you don't want two/four extra connections in each feed, you can ask if the electricians will run up to 333 ft (up too 100m) pre-wired male to male cables. Some won't want to.
If you want a full house camera setup it's fairly easy to figure out where to place them and how many you need. Hold out your arms in front and off to the side of you, to where there is about 110 - 120 degree arc between them, then stand where a camera would be directly over your head, so you see roughly what a camera would see. Then set up a "chain" around the house where each camera sees the one in front of it (or behind, as long as each camera is seen by at least one other camera). Although, full home coverage is probably
a bit of an overkill. Small note: to catch faces well, at least one camera needs to be head height or lower.
Not sure how Ubiquiti cameras stack up, but the Google, Amazon, and whatnot didn't seem very highly thought of by the enthusiasts. All of them have network security concerns and I am dubious that any of their motivations are much better than the CCP. Therefor I would never let any camera system connect to the internet though their own software. Although, since Ubiquiti is already a network security company with tens of thousands of professional level eyes on them, I would pick them as the most likely to be trustworthy in that regard.
The security people seem to like BlueIris 3rd party camera software running on it's own server for all that, but I didn't spend much time looking into it. It is supposed to be great for large systems.
IP Cam Talk was the best enthusiast site I found for security camera stuff:
https://ipcamtalk.com/wiki/
Edit: Defiantly use larger PVC pipe (or conduit) in the walls for the main internet/security/server hub or closet but if the places where your mounting the cameras has attic access, it's usually not that bad to run
more wires to it (not sure why you would need to). Hell, if you ever need to replace any of the Cat-6 with something else, you just attach the new wire to the old and pull it that way.
Edit2: If you don't want your whole house lit up all the time, think about researching infrared flood lights to go with each camera. Many camera's come with infrared lights included, but more light, in a better spread, it going to give better nighttime quality. Good floodlights in full spectrum is best but not everyone wants motion lights or fulltime on at night floods lighting up the neighbors. There is also the issue of glare if one of the flood lights is shining toward a camera.