DoorKing service, 3g sunset and upgrade...alternative?

So we have a gate and a key code. We are paying $50/mo for DoorKing service, which I think means that someone can call your # on file, then you page them in through the gate.

It seems the old 3g system is sunsetting and we will need to upgrade components, at a total cost of $1030.

So My question here is: what do you use for your gate control? It seems that there is not a single person in my small gated street that uses the call-open feature, let alone knows that its an option. Has anyone cancelled their DoorKing service? Has anyone rejected the 3g upgrade?

That would be I deal if everyone was on board to use their clicker to enter the community, but you need to have a USPS keyed access for the mailman, and UPS, Fedex, Amazon deliveries.

I myself would be interested in an iot app based system with a QR code type scanner that could act as a virtual gate attendant for visitors and deliveries.

Iot is an internet of things. I am researching virtual gate attendants where people can log into the system or a manager can log into and issue temporary parking passes or one at a time deal.
There would have to be an wifi connection at the gate with a QR scanner reader. the owner logs in and issues a parking or entry pass and the visitor opens an email or push notification and scans it at the gate.
for extended stays the owner would need to print out a pass to place on the cars dashboard. I feel a system like this does not quite exist yet.