You are going to get a lot of opinions and I believe it comes down to what your are comfortable with. I am very happy with Hubitat controlling my home security, while understanding that it is not a top notch professional grade security system. But I believe it is better than what I had in my house.
My House before Hubitat Security: Security System professionally installed by one of the largest Canadian Home Security Companies. This included door and window sensors along with a control panel that had battery back-up. In case of a break-in the security company would be notified, they would call the house to check if there is a false alarm and send their own security patrol. If their security patrol found something wrong the police would then be called. Cost of monitoring $250.00 per year.
My House with Hubitat: System installed myself. This system includes door sensors, window sensors, motion sensors, and POE cameras running Blue Iris. Immediate notification on my phone when the alarm is triggered. This Includes a video link to my cameras and what is going on. I will also get an instant notification on my phone if my cameras detect motion while my alarm is armed. Blue Iris camera software plays nice with Hubitat and the customization options with all the sensors and cameras allow for me to decide my personal level of comfort. If the alarm is triggered, I know instantly if it is a break-in (camera feed) and I call the Police myself. I consider this superior to my previous professionally installed and monitored security system. Annual cost of monitoring $0
Are there other options better than what I mentioned above, absolutely. I may consider one of these one day. But for now I consider myself better off than I was before. I have everything local (other than Hubitat app notifications) and I pay no monthly fees.