Well, downloading Minecraft from unknown website is very dangerous. Sometimes you device can be hacked and sometimes you device can be closed permanently because of virus. Because whenever you visit a website for downloading Minecraft you don't know what inside of the link you are clicking on. 
But still, about more than 50% players of Minecraft are playing the free version which are downloaded from different website in their mobiles but for PC everyone use launchers.

Downloading Minecraft APK files in PC from unknown website is a very dangerous than downloading APK files in mobile from unknown website. 

As a experienced user of PC, I would like to suggest you not to download any kinds of creaked games from various website. But if you do that then you will gonna to be in a big problem especially for Windows. 
If you have enough money to buy Minecraft from the store then do it but if you don't have enough money then I would like to recommend you to play Minecraft(java) using launchers like tlauncher, luner etc for PC.

But if you are a mobile player of Minecraft(bedrock) then you can download from unknown website means you can take risk. But if you are scared about to download from unknown website then visit here. [It's totally safe]