i think it's you because of 3 factors
1. taiko has a very stric timing window for getting 100% on each note compared to other game modes
2. i think you didn't play enough to get the feeling on where to press.
3. i have friends that use really low-end pc and they can hit better than me and my very good setup
as Endaris said, at the beginning it's harder to keep the rhythm as there aren't many notes, even tho i think that is just another skill to learn: hitting easy stuff consistently
a tip i have for you is to use the score meter type, as it helps you understand if you pressed a note late or early
(i never use it but it's probably just maybe because i have other rhythm game experiences?? idk)