Some doctors can get the several hundred thousand dollars, but many of them fall for scam investments and lose it all in them. Teachers are more likely be investing in safer things than a real estate deal. An index fund (or similar) will give you more diversity for the same investment and so is a lot safer, it won't grow as fast in the best case, but it won't drop nearly as far in the worst case. (I recommend target date retirement funds these days for even better diversity).

Not that real estate is a bad investment, but a single high value deal has no diversity and so it a bad investment. If you are putting several hundred thousand into a single investment your net worth really should be closer to ten million than one.

Note that I said some doctors above. If only 1% of doctors are good with money/investments, that is a lot of doctors, and they will in general have more money than any teacher.