Yes.

After all, Bitcointalk isn't the only source of knowledge when it comes to cryptocurrencies. I mean there are many websites out there that can give as much information as Bitcointalk can give (or even more). Though I don't personally know any investor that isn't registered here (I don't know many people around me that's invested into crypto), I still believe that there are some who became successful investors even though they aren't joining any forum.

There are many ways for an investor to gain knowledge. There are many social media platforms out there that gives information as well. Well, when there's many information, there's also many of misinformation out there so just be careful.