What's the point in children being in school if the teacher can't communicate effectively?
They manage OK in other countries.
I understand that there can be issues for the minority of children who have hearing issues, but there are ways around this, or worst case scenario there could be discussion about homeschooling children with significant hearing difficulties for a while until vaccine coverage is good enough to ditch the masks. Because yes, having 2% of kids homeschooled is better than schools being shut for everyone. And I say that as someone who has some hearing difficulties.
Bear in mind that the corona-friendly classroom settings that are being used in a lot of schools (front facing separate desks) also have some compensating advantages for children with hearing difficulties.
I am deaf in one ear and sometimes struggled with primary classrooms due to the UK system's love of clustering children around tables (=blocked view of what was written the board, and nonstop chit-chat and distraction among the children).
I found things much easier once I got to upper secondary because we sat at our own desks and faced the front at all times and could see what was on the board without having to twist round to look at it, and the front facing, spaced out seating arrangements meant that there was very little background noise in the classroom.