There was a time when to get advanced functionality (and sometimes even the basic functions) you had to root your Android device. But we have come a long way, and Google has loosened up the tight grip it had on its mobile OS; so much so, that there is no longer much need to go the rooting route anymore.
When you root your device, you essentially operate as a superuser on a Linux kernel (Android is actually based on Linux), and you get a deeper and more unrestricted access to your device administrative rights.
Back in the days, Android had a lot of limitations. You could even do simple things like taking a screenshot without rooting the device. Turning off GPS from a widget also required rooting. Nowadays, there is more freedom on the mobile OS. The OS has since become more open, and most of the tasks you could only do by rooting can even be done using third-party application.
However, there are still some people who find Android restrictive. To enjoy the platform they will need to root.
Rooting Android device these days is still hard; if not harder
By default, Android is not designed to be rooted; at least most of them. The system is built to lock you out, and there is no legitimate way for you to get in. Ironically, phones that are exceptions, the ones that let you root much easily are Google phones. The likes of Pixel and Nexus.
Most other Android phone brands make it deliberately hard to root. You will need an exploit to gain root access. The Android hackers and phone manufacturers play a game of whack-a-mole; as soon as the hackers find the exploits, the manufacturers work on releasing a patch. Thus making rooting an Android phone extremely hard.
In the old days, exploits were plenty, and manufacturers were not as swift (or keen) to issue a patch as they are these days. For those reasons, rooting an Android device these days take a high level of hacking skills to safely root. Manufacturers’ try to make your sweep through tons of forum posts, guides, tools, and exploits before you secure a possible root. And when you do, there is a big chance you will not execute the root safely leading to you damaging the phone permanently.
The best you can wish for when executing a root is to softbrick your phone, where you can fix the damage or learn to live with it. However, chances are high you will totally brick your phone; unfixable.
Leave the Rooting to the Experts; people who know what they’re doing
You might be wondering why can’t manufacturers let you access root easily out of the box? Well, if that were the case, the non-technical user will easily mess with the wrong settings leading to big security holes. Then one thing will lead to another and law suite, and bad PR will bedevil the manufacturer’s brands. That can happen to many consumers across the market, and things will go south for many sectors of the economy.