I tried out Superpowered and while it's more polished than its competitors, it has a few downsides other commenters have already touched upon (pricing, memory use, and personally, the name hits too close to home to Superhuman.)

I've found that the best alternative is Slapdash. [0] Connect your calendar and then just hit cmd + J and boom -- Zoom is running. Many more connections are amazing as well, eg. deep Dropbox and Drive integration.

[0] https://slapdash.com