Can't decide between Mandarin or Japanese

I've had this exact dilemma for so long that it's gotten to a point where i've progressed past the very basics of each language and can read/form basic sentences now. I know hiragana, katakana and some basic grammar for Japanese, and I know pinyin, basic grammar and some basic hanzi for Mandarin.

For a while I thought that I should learn both at the same time but plenty of people on reddit advise heavily against it so i've just been "dropping" one language, going to the next and having the cycle repeat. For context I live in a part of Australia where I regularly meet Chinese people (most of whom speak mandarin). We even have several Chinatowns so communication and finding people to speak to wouldn't be an issue. I've also been interested in the history for some time and It's known to be a good language for business - particularly in this country.

However...

I've always been heavily interested in Japanese culture and regularly consume media in Japanese whether it be in the form of music, shows or games. I can definitely see myself using the Japanese side of the internet more even if we're just talking about internet chat forums and discord communities.

I'm stuck between learning Japanese and immersing myself in a language I've always wanted to learn with media that I already love to consume on a daily basis, or learning a language that would be more "practical" for me and that I can use to communicate with in real life. I guess Japanese would be online and Mandarin would be offline in this sense. I know that I'd enjoy learning both and wish that I could just study both at the same time but I don't think that's a good idea so I hope to find some clarity.