My experience at big corporate is that (edit: unmanageable) tech debt is caused by undisciplined and unorganized scrum team.
When you have a proper backlog of tickets, including tech debt tickets, the team will eventually fix the tech debt when there are not enough feature tickets to exhaust capacity.
When you have a proper backlog of tickets, including tech debt tickets, the team will eventually fix the tech debt when there are not enough feature tickets to exhaust capacity.