it is a bit blunt but it’s supposed to help to correct for your room/sitting position
of course there’s lots of other things you can do to set up your room that will probably have more of an effect than the standard high & low +/3dB cut/boost - simple monitor placement and decoupling make a big difference
there’s quite a lot of software for testing room setup
to make up for mic biases the shop bought packages come with their own calibrated mics, like this one
https://www.ikmultimedia.com/products/arc2/
but any dynamic mic with a decent frequency range will still give you enough to make improvements. I set mine up with with a ‘borrowed’ version of the ARC software and an SM58 (though I should probably redo it as I’ve moved my room around - for the better - since then)
There’s doubtless apps calibrated to your smart phone mic too
you can also do it DIY using white noise and a spectrum anaylyzer (though your white noise source will have to be pretty pure). The IK ARC version I have uses a low-to-high frequency sweep which is LOUD. It’s quite disconcerting actually to be able to hear your own room resonances, holes and monitor response in real-time with a 10 second tone sweep (and your own hearing limitations). Kind of cool though