Bitcoin does not necessarily need advertisment because when something is too good it can't be hidden, it is a choice to either invest in Bitcoin or not, advertising Bitcoin now is not something to be bothered about because it has pass that stage and has gotten the recognition needed . Investing in Bitcoin should become more of self convinction and not because it is what every body is doing or talking about, who will invest will invest and who will not invest will not invest irrespective of how much discussion and adverts.
Seems you are missing the point on what advertisement is and that have to be corrected. The news you see on the print media, the hypes and all the excitement about the bull run are all different forms of advertisement. Even FUD can be regarded as a form of advertisement because there is a popular saying among politicians that "negative publicity is better than no publicity". This was what helped Donald Trump in his election 2016, where the big media portrayed him in a bad light yet people got curious and did their independent research and that helped his popularity. So, Bitcoin thrives so much on the news which is also a form of advertisement and there is no point pretending about that. You can say that Bitcoin does not require anyone to spend money running ads on big platform as the its advertisement is done free of charge with many of those pushing it not realizing that they are actually marketing Bitcoin.
To be frank with you, without the news about Bitcoin spreading in the print media, most of the people that are invested in Bitcoin might not have even known about it. Some of us here came into Bitcoin because we heard about it from friends, social media or different platforms. I agree with you that investment in Bitcoin is a personal thing that does not require any convincing but the potential investor must first be aware of Bitcoin through someone or some means before taking that personal decision to invest.