in my opinion when compared to brave, in terms of the concept even though both use a browser, of course brave is better. nimiq still has a little potential it's just not able to defeat the brave (bat).
I don't think it makes sense to compare Nimiq to Brave/BAT:
- Nimiq
uses a browser as any other web app. No installation is needed as it runs in whatever browser the platform provides. The main use case of Nimiq is web payments for everyone, to replace PayPal. The code is completely written from scratch.
- Brave
is a browser and cryptocurrency light client in one application. It is not installation-free, it's a normal desktop app (and most people refuse to install such). The main use case of Brave/BAT is to change/replace advertisement/tracking industry. Brave is basically Chrome+AdBlocker+Cryptocurrency+Marketing, thus the technological advantage of Brave over just using any browser with a few plugins (Metamask,uBlock,...) is limited IMO.