Trac was great 15 years ago, but now Trac is a dinosaur. It would be somewhat redeeming if it was at least fast, but it's mind numbingly slow. Before we eventually ditched Trac we had to buy ever faster hardware but requests could still take 20 seconds. Git support in Trac is an afterthought (It started as svn-trac after all!) so pull request management etc is either missing or handled by plugins (and most trac plugins seem inactive or defunct by now). Trying to get a good mobile experience, slack integration I haven't even tried but I assume it's no picnic.