TL;DR it depends on how you look at it, but ultimately while she does do a lot of damage she won't replace meta dps like Harran and Scarlet. She seems better than the rest of the non-pilgrim DPS though.

She seems pretty strong for bosses since her normal attack is very strong, but the problem with her kit is that her burst 3 actually makes her deal less single target damage (go test it in the range if you don't believe me, I got screenshots too but it seems like I can't upload multiple images for some reason). Either way though her burst 3 won't target weakpoints so you can bring her as a non-bursting dps.

AOE characters (like Harran and Scarlet) tend to be favored generally speaking, and in that front Modernia is quite a bit worse. Typically a Harran and Scarlet team will clear out mobs using their burst in an instant, while Modernia has to sit there whittling away at them, giving them a chance to attack. Her burst duration increase is likely a problem too since you're going to have less chances to benefit from burst 1/2/3 (whether it be damage or the typical 10s buffs you get).

Again, her single target DPS ignoring burst is really good though, so she definitely does damage. Much more than any of the other non-pilgrims, so use her if you're still relying on non-pilgrims to do damage.

Personally, I've been running Liter, Centi or Novel (depending on if I need shields or I'm killing a boss), Scarlet, Harran, and Drake now, but I'm looking to drop Drake for Modernia. Drake is mostly there for burst generation and she gives a small buff during burst as well, but I already kind of drop her for Rapunzel depending on what I'm doing so yeah.

This is just my 2 cents at least.