Answer:
The burden of taxation was so great on the peasants
Tge artisans and the middle class were upset because their population was mostly peasants.
Step-by-step explanation:
Russia had no form of income tax. The Tsar taxed the produce of the peasant farmers to raise money to maintain his regime. The burden of taxation was so great that periodic riots broke out. The peasants of Russia had been freed from serfdom in 1861 by Alexander II.
The reason why the Third Estate was so unhappy was because they had 95% of the people which were peasants and they were treated poorly and overlooked by the two other estates.