I just use Gcal. There might be something better but I've never stuck with any alternatives. I wish Superhuman would build a calendar app!
Perhaps the most well-designed and keyboard-driven calendar I've used is Fantastical. Much like Superhuman is to email, it feels specifically designed to make managing events fast and simple. Its natural language processing is amazing for creating events just by typing out a description. And newer versions pull in weather, help with managing timezones, and more.
Even if it's not brand new software that first came out in 2019, what new tools have made you more productive this year?