It increases security in certain circumstances. Mostly for Windows users at big corporations.

For example, you want your users' laptop hard drives to be encrypted - but also you have users who regularly forget their passwords? With bitlocker their hard drive can decrypt itself, so they only need to remember their windows login, which you can reset remotely.

You give laptops to your field workers, who have full physical access and would love to play video games or access netflix when work puts them in a hotel over night with nothing to do? With secure boot you can keep your precious spreadsheets locked down, even if they're willing to boot from USB sticks or swap the hard drive.

And perhaps most importantly, it has "secure" in the name. So the corporation's IT security auditors will like to see it turned on even if they have only a vague understanding of what it does.