Actually wearing plate, you still might want to use a shield.
Even though plate provided the best protection for its time, you are still better off “not” getting hit. If you weren’t using a two handed weapon, it wouldn’t make sense “not” to have a buckler or shield with you, to block blows and hits, rather then just letting them hit your armour. Plate wasn’t invunerable after all, maces, picks, and axes were great to use against it.
As far as weapons go, in the video it says swords are weak against mail, it depends on the sword and attack actually. There were swords made specifically to counter plate. The Estoc for example, a long tapered blade made to thrust inbetween the links of chainmail.or against plate in the weak/open areas. It had a longer hilt and no edge, rather it was developed to be mainly a thrusting blade to counter the armour of the time.
Regarding Arrows, this is where the difference gets more varied. Chain could be vunerable to certain arrow types , those that were mad to counter it, with long thin tips that could get betweent he links.
However Plate armour? It was pretty much invunerable against arrows for the most part. It’s a common myth that a bow , especially longbows, or “bodkin” arrows would stop a guy in plate. In order for an arrow to pierce plate you have to be at an EXTREMELY close range (to the point as an archer you’d probably want to be running the opposite direction) or get lucky and the arrow finds its way into the weak area of plate (joints, neck, visor) which could happen.
Ths is one of key things that made plate such valuable armor at it’s peak.