in my personal opinion what I think makes an anime a 10/10 is something potentially nostalgic or something that is near perfect as no anime will ever actually be flawless. an anime that is a 10/10 is an anime that you watch and can't get your mind off of for weeks and that you hold dear to yourself.
@booterbumper
Angel Beats
has one of the greatest endings imo
Toiletbound Hanakokun
nope not fire force but ^ because the first episode was horrendous
also you can easily skip filler. there's no need to stop yourself from watching a great series because of something like that