If you could only do one marketing strategy - X, LinkedIn or Reddit? Why?

I think it depends on your audience. There's a particular kind of person on X and a particular kind of person on LinkedIn. For me, the audience at totally difference. So I think it really depends on your product and who you're trying to reach.

since my Niche is crypto... X is the place to be... no other platform will do... Telegram maybe. but thats about it

I recommend utilizing LinkedIn as your primary marketing strategy. LinkedIn is a professional networking platform where you can connect with potential clients, partners, and industry professionals. By sharing valuable content, engaging with your network, and participating in relevant groups, you can build credibility and generate leads for your business. Plus, LinkedIn's advertising options can help you reach a targeted audience effectively. Good luck with your marketing efforts! We are building a marekting AI called Contentify AI. It's free and easy to setup. Check out the "Launching soon"

It dedepnds on your product. But the statistics I recently saw claim that conversion rates on LinkedIn are significantly higher than on X.

LinkedIn and X are where you want to be - Reddit is not as good for promoting your launch these days. Have you considered a social media management platform that allows you to post/schedule to multiple networks at once?

Instagram on top, according to me and my observation, the users are mostly active on Instagram, with lot of cool people present. New upcoming generation are more friendly with Instagram. And also, if you want users which will use your product and services in long run, they got the potential. For long run, mostly for products, this "GenZ" should be your target audience and to target them and make a mark about your brand, find them where they are mostly active, and that is Instagram.