Has Vivaldi always been available for Linux? I could have sworn when I set up my Linux computers a while back Vivaldi wasn't available. Maybe I just missed it.
Vivaldi has been available for some Linux distros for about 6 months or so. Depending on the Linux version, it may not show up in the software manager. I primarily use Mint Cinnamon and had to download it, initially, from the Vivaldi website. It does now show up when it needs to be updated.