Most of the world is closed source and if the only reason to not use Vivaldi is because it is not open source well that isn't a very compelling reason at all. Most of the planet is using some form of closed source web browser the top 3 being Chrome, Safari, or Edge.
Well, no, it can be a compelling reason and the world can still mostly run closed source browsers. Those ideas are not in conflict.
Twenty years ago if you said "don't run closed source operating systems" people would've popped out of the woodwork and said the same thing. Twenty years later, a huge chunk of the world runs on an open source OS.
I suppose a lot depends on how we define 'world' and 'open source'. Still, there is an argument to be had ( and what FSF advocates ) about benefits of open software. "Closed source" is absolutely a compelling reason and, from where I sit, companies and organizations across the globe have shown time and again that they simply cannot be trusted and will engage in 'goodwill withdrawal' when convenient.
<< Most of the planet is using some form of closed source web browser the top 3 being Chrome, Safari, or Edge.
Sadly, I personally believe popularity is a bad reason to advocate for technology. I kinda buy your argument that 'closed source' is not inherently bad ( edit: but it does require trust hence my first paragraph ).
I use a closed source browser but I don't use Vivaldi because it's slow, drains the battery on my laptop at an incredible rate and I find the UI to be less than enjoyable.
