I am struggling to understand how Bitcoin is going to be used.
I know its long standing coin, gold like qualities, not hackable etc. But when it comes to how it can be used, I could not find any answer. High transaction fee, limited coins cause deflation, too volatile etc. General public, corporations cannot use it. Gold is different, there is nothing like gold but we have better coins than this.
Will this be used for only speculation, betting? How would general public / institutions use it in future?
It is used all over the World daily to trade and also for eCommerce on websites all over the internet. The high transaction fees is a total myth these days, because if you use SegWit addresses or the Lightning Network, your fees are almost zero.
High volatility can be eliminated if you use Payment processors.
Gold is ancient and old school and cannot be used for global micro payments, because it is simply impractical for someone to use Gold. It is already used for speculation and for online gambling and this is one of the strongest forces that are driving it's price.