In a nutshell: It's the difference between renting and owning.
Social media platforms will come and go. Streaming services will rise and fall in prominence. The most important thing you can do is harness the relationship with your fans. Remember, you rent your fans to social media, you own them when you have them on your mailing list. And you own your website. Social media and streaming platforms oftentimes flip the algorithm overnight and you lose access to your hard-won fans. Make sure you are developing a long-term relationship with your fans to support the life of your career – not just the trend of the moment.
No matter how many followers you may have on any given social media platform, how many hours you spend DM-ing or commenting back and forth with them on those sites, in the end you're just renting their information. Because those sites can come and go in popularity, the algorithms change constantly-- how often you do you hear "Oh, I just saw your post, wish I'd known sooner!" days after you posted about a show?-- you're constantly having to jump through hoops to be heard above the noise and stay top of mind.
But if you have their email addresses, their phone numbers (a mailing list you harness through your website), you can connect with them directly. Not just to announce your shows in a more timely fashion, but as a way to start developing a community of super fans-- folks who want to engage with you more and more and feel personally invested in your success.
Now don't get me wrong. I'm not saying you shouldn't do any social media. I'm saying you shouldn't count on it as the only way anyone can find you. You should ALSO make sure you have a piece of internet property that's completely your own: your website.