At the end of the day it comes down to raw economics. In a lot of the West (I think places like Scandinavia and Asia/Oceania are exceptions) education is woefully underfunded, which translates to wages, too.
How are you supposed to attract talent when you're trying to give your teachers maybe a third of the wages they'd get in the private sectors? Tutors make bank. Translators (for foreign language teachers) make bank. I'm not even talking about the various other field-specific jobs they could possibly get instead.
Then there's the issues of funding which in extremes mean that teachers have to dip into their own already meager salaries to buy basic supplies for their classes.
It's just a ton of hassle with little payoff. There are some wonderful people out there who are genuinely driven to be teachers and try their best to give the future generation a good start in life but those are a minority compared to people who consider a job just something to extract money from, and that's not something we should try to change in people, instead we should actually fund the education system as well as it should be funded.