I know a lot about both Chernobyl and the real USSR, and while Chernobyl obviously didn't lead to the collapse directly, it absolutely played the key role in destroying people's trust.
>There were HUGE amount of very different (and quite known to citizens) disasters before Chernobyl
Like what? Three most known disasters of the late Union were Chernobyl, Spitak earthquake, and Ufa train disaster, and the latter only became known because of Chernobyl which opened the valve on the freedom of the press a bit. All three clearly showed three things:
- that government was completely unprepared to natural and man-made disasters, so that the Army had to be involved (MChS was created in Russia after the breakup precisely in response to that, other republics did the same, largely)
- that the party didn't have the interest of people in mind, and was concerned with covering their own asses up first. People responded in the same way - just listen to 'Я вынес из Зоны' by Sergey Uryvin, it's a nice illustration of the atmosphere during liquidation.
- that Glasnost didn't work very well in practice
>Moreover handling of Chernobyl consequences was a much better than handling of other disasters of the past.
Only because it happened in a populated area, was not restricted to military, and was practically impossible to downplay or deny due to that. They still tried, demonstrating that Glasnost was only a declaration with little substance.