You should understand that you don't own your content while posting on social platforms. By signing up on a platform, you agree to their terms of use, which are mainly designed to protect the platform's rights rather than your rights as a content creator. You have limited control over your content on some platforms - you may not be able to edit or delete it, and your content is often stored on backup servers even after you delete it. Moreover, the overwhelming majority of social platforms don't guarantee freedom of speech. This time around, when cancel culture could terminate your online presence without trial, you have only one way to protect your fundamental right to freely express your thoughts. It is the mean old website.
Having a personal website is a clever investment strategy. You own a domain name, which can be bought for an unlimited amount of time, even for decades. When you have your own domain name, you have the flexibility to choose how you want to manage your tech infrastructure. This means you can even have your own server. You also have the freedom to switch hosting providers if your current one doesn't meet your needs. You have the control to monetize your content by implementing different kinds of advertising, such as contextual ads or banners. Most importantly, you have control over your own information. The only way your domain name can be taken away is if someone takes you to court and wins a judgment against you for harassment or defamation.
Some might argue that there is an issue with engaging an audience. Undoubtedly, the main benefit of using social platforms is the ability to reach a wide audience. The most effective way to safeguard your freedom of speech is to first publish content on your personal website and then share teasers linked to it on selected platforms.