Do you have a friend who already owns the game on Steam? Ask them to enable Steam Family Library Sharing.

Needy Streamer Overload Community Features:

While not the full game, some fan-made visual novels on Itch.io replicate the “messaging simulator” style. Search for “Streamer simulator demos” or “denpa free games” on Itch.io. Standouts include Internet Love Story and Ctrl+Alt+Despair.