The increased scrutiny is bewildering to Ms. Young, 33, who recalled how, after the Parkland shooting, she brought a leather belt to store in her classroom first aid kit, in case she ever needed a tourniquet for a student.

“It’s being literally entrusted with their lives,” she said, “but not entrusted with choosing curriculum.”

Teachers in public schools make an average of about $65,000 a year and have been among the most trusted professionals, alongside nurses, doctors, military members and scientists. But as schools shut down and social fabric frayed during the pandemic, trust in teachers declined.

For some, the competing pressures have been enough to walk away.

“I needed a change,” said Kathy Macken, 62, a math and science teacher in Richardson, Texas, near Dallas, who is leaving the classroom after 19 years to do intensive tutoring with smaller groups of students.

After being out of school earlier in the pandemic, her fifth graders came back this year in great need. Even as she tried to help them academically, Ms. Macken said, she spent much of her time trying to keep them calm and focused: Get out a pencil. Write your assignment in your planner. Please, no iPads during story time.

She had to scale back a favorite science project — where students build terrariums to take home — because she did not have time.

And in the last week of school, a lockdown interrupted an outdoor field day. Amid tug of war and fun in a bounce house, students were hustled back inside. Ms. Macken huddled with her students on the floor of her darkened classroom while the police investigated a report of a teenager walking down the street with a rifle.