I don't understand why you asked the same question thrice, lol 

Anyway, since you have been in the industry for a few years, you should know that Bitcoin was the very first cryptocurrency ever created, and when it was created, it didn't get popular in a month or even a year, it took a lot of time for Bitcoin to gain the recognition it has today, and the reasons are obvious.

The very first reason for Bitcoin to become popular was that it acted as a peer-to-peer electronic money transferring method that was decentralized and private which means no central authority or any individual was controlling the network or the transactions or anything, it was all done by a system called the blockchain. People came to know about this thing initially, and they liked it, so they started using and promoting it, and slowly over time, it became very popular, and the rest is history.

Today, though, the vast majority isn't in it for its decentralization or financial privacy it provides, but most people are in it for the profits.