Thoughts on Current Home Alarm System?

I’m under contract for a house that has a Napco Gemini P3200 system. It looks like the system includes motion sensors and smoke detectors connected to two keypads. I’m not sure if the sensors are hardwired yet (we don’t close until the 27th).

My question is: Is this system worth upgrading or sticking with? The current owners use a landline for monitoring, but we don’t plan to have a landline. I spoke with the original installer (still in business), and they mentioned that we can switch to cellular monitoring, eliminating the need for a landline. They also said we could control the system via an app with some upgrades.

I’m trying to figure out if it’s worth upgrading this system compared to newer options available before investing in cellular, touchscreens, etc.

Thanks in advance for any advice!