Gold ETF is much better in comparison to Physical Gold when taken from the point of investment.
The reason behind that is, Gold ETF has each unit price according to 1 Gram of Gold with 99.99% purity (So you dont need to worry about purity).
Another thing, it is in Demat Form, just how to own shares in your demat account (So you don't need to worry about its saving, physical location of Gold, or even of loots and theft)
Apart from this, the another thing is, while going for Physical Gold, you pay about 10% making charges and 5% about breaking charges when you sell the physical Gold, whereas there are no charges at all except the brokerage (which is hardly 0.05%) when you go for GOLD Etf.
So these were the benefits of trading in Gold ETF, another thing that I wanted to say is, Gold trading in MCX is even better than Gold in ETF, but that is more for trading and not for investing, so if you look from investment views for long term, ETF is undoubtedly the best option. And for trading, GOLD in MCX is the best option.
Hope this helps.
Regards!