To each their own. HN users prefer light sites like HN itself so Leantime with material styles is not ideal for lightness. Pivotaltracker and Redmine are really nice with basic-looking UI.
Though I've just set up Leantime in my homelab for todo list/calendar.
We have some overlapping feature set but I would argue Leantime looks a bit better but I may be biased :D
The key differentiators are our goal and strategy tracking though.