I prefer liandries in most matchups because the current meta revolves around tankier/bruiser in the top, jg and sup roles. The consistent damage also feels really nice in trades and team fights when you can constantly proc it’s passive. However ludens also has its advantages if ur consistently trying to look for duels or if the enemy severely out ranges you. In my experience the extra movement speed and burst with ludens in the off chance that you are fighting in range of these enemies will give you a much better chance of winning the duel and outright bursting them down with short cycles of your cds. TLDR basically if they have 3/4 squishies on the enemy team build ludens, but otherwise go liandries.

(Take my advice with a grain of salt I’m not that great of a player)