In comparison to the standard antenna included in the packaging, your consideration is an improvement in terms of gain and V.S.W.R. and might provide an improvement. Though the gain value seems to be exaggerated.
If your device is located in a stationary spot and you know the direction of a cell tower, I would suggest to consider a directional antenna.
An example could be this unit: https://teltonika-networks.com/product/3rd-party-rut240-outdoor-directional/. Keep in mind that this is an outdoor unit and you will likely need to consider additional passive PoE injector for this specific antenna to power the RUT240.