As a retail trader I prefer desktop heavy apps rather than web based ones. I believe what is missing in the crypto space is an algotrading app that allows me to code my own strategies and indicators.
Also, have you tried TradingView? What do you think about them? They have scripting for strategies and indicators. It is an array-based language, I think, somewhat similar to R, just simpler. Nevertheless, I was able to craft quite interesting things in there.
As for desktop apps vs web-based: desktop apps definitely have their uses and advantages. I'm not saying web-based is better, but I think it's just more approachable, and there are ways where some of the existing apps might be improved.