any reincarnation or transmigration wherein no magic, powers, demons, monster or something...

This is BL tho, hope its ok.

https://www.mangago.zone/read-manga/the_affairs_of_the_other_world_depend_on_the_corporate_slave/

https://www.mangago.zone/read-manga/inso_s_law/

https://www.mangago.zone/read-manga/the_villainess_s_18_year_old_attack_story/

https://www.mangago.zone/read-manga/july_found_by_chance/ also this if you don't mind the fantasy part where there's heads = forced scenes where she has to act out the plot & tails = scenes where she is not actively important in the scene and has more freedom