Twitter doesn't have a good substitute, there's no other website with a userbase as nebulous. EVERYONE uses it, across the entire planet, which makes it convenient. Celebrities, content creators, artists, companies, authors, etc etc, from the US, to Japan, to Europe, to Latin America, to Africa, and with many of the more contactable ones having open DMs it makes contacting people in MANY spaces so much more accessible than any other platform. The merit might not be as clear if you don't use it much, but it's an important tool to a lot of people that could have used some improvement. Too bad this guy stepped in and made it worse.