Which components are more important on an entry-level MTB?

Hi everyone!

I'm looking at an entry-level MTB for my father. I see different brands with various builds. For example some of them are with better tyres, cassettes, rear and front derailluer, drivetrain but less of a good fork. Others are putting a better fork on a bike but with less quality in everything else. Which one you would go for in the end?

Thank you for your advices!