Yes there are MAJOR drawbacks to rooting... while it does let you do some things accessible for change... it does mean that you can break some stuff... to the point where you have a shiny paperweight in your hand instead of a phone.....
Make sure you read, read, read... and know how to recover your device back (if you need to re-install the software again a simple factory reset will NOT do it for you)... with a well supported device like a G4 plus you should be able to do this.. with a generic cheap device you stand no chance...
Also, some Apps, won't work on a rooted device, these include Banking, TV, and some games like Pokemon Go. Whilst there are ways of cloaking your device from these, they won't always work.. As you mentioned.. OTA updates can cause major problems for rooted devices... and of course some manufactures may consider rooting to void your warranty.
Am I saying don't root your device? NO, I'm not saying that. A couple of years ago, you needed to do that do a lot of things... these days, the need to root (for most people) isn't quite as compelling. If there isn't a reason why you need to do it, you might want put it off for a while , and just enjoy your device.