In electronic music, typically only two instruments contribute to the bass frequency range: the kick drum, and the bass. But then, any melodic instrument with a low fundamental can serve as a bass.
It doesn't mean they don't contribute to the other frequency ranges. In fact, they often have very rich spectrum, especially in more aggressively sounding genres. This helps them to be well audible and defined. This also helps the mix to sound well, even if the low frequencies are not well reproduced, e.g. on phone or laptop speakers etc.
Also, as electronic music is a purely artificial creation, no conventions need to be followed. The bass can be the lead melody instrument at the same time. A strong, wide frequency range sound can serve well for such purpose.
Finally, it is common for the preset sounds to be very rich and dominating, perhaps to impress the user, but also to showcase the capabilities of the instrument. If you want to use such preset in your own mix, don't be afraid to cut the frequencies, or tone down parts of the preset, which collide with the other instruments. It might be that the best sound for a particular mix isn't necessarily the most impressively sounding on its own.
One more suggestion regarding browsing instrument presets is to play with the modulation wheel (and other additional modifiers used by the instrument). If the preset creator took care to assign it to some parameters, it may open a whole new dimension of the sound. A bright, aggressively sounding bass sound may turn into a muffled, subsonic murmur – or the other way round.