This is quite true. RAM or Random Access Memory is like a file cabinet, all the things you put in this file cabinet is easily accessed once you need it. But RAM is not the only thing one should consider in determining the quality of a smartphone.
RAM is only one of the component in all smartphones. There are two kinds of component digital and hardware.
Digital component is pertaining to software, applications, themes, and system files. Hardware components are pertaining to physical parts like CPU, Bluetooth,WIFI, and of course RAM.
Now all of this components are all important in order for a smartphone to work properly. But why most people consider RAM as one of the key specifications for buying a smartphone?
Its because of speed !
Although CPU is one of the most important hardware component on smartphones. RAM is your guy for speed for data processing. While CPU is the brain that commands all of these components to do what they are told by the user. The RAM is responsible in data traffic.
For example you opened your internet browser in your smartphone, the CPU will command the WIFI, browser application, and system files to activate. This is where the RAM comes in. In order for the WIFI, browser and system to do their work in a fast pace...All the the data are given to these components by the RAM simultaneously.
Let's put it in a different perspective.
RAM = Highway
1 highway = 1gb
Now if you have 1 highway you will have two lanes.
Lets consider these lanes as Request and Recieve.
At 1gb of data you will have the speed of a 1 request lane and 1 receive lane.
Just like any highways sometimes there will be traffic or bottle neck.....it could be too much car on the request lane or in the receive lane.
In order to remove congestion on traffic we must add more highways.
Imagine if you have 4 highways (4gb). The speed of the lanes will improve dramatically.
That is why RAM is so important. You don't want your smartphone to be in traffic

.