What makes you think that a replacement government wouldn't be equally as bad, just in a different way?The problem here is that after what happenned in Ukraine, Moscow is very unlikely to let that happen and the leaders of the internal security forces are much more probably in contact with their opposite numbers to the East rather than looking at what the Belarusian population wants.
The problem for the Kremlin is that the Ukrainian people set a major precedent by overwhelmingly rejecting any notion of subservience to Moscow. If the Belarus people were to follow suit then there is another example for the Russian population to emulate and finally get rid of the "Muscovite Mindset" that has so thoroughly muzzled the peoples of all the Russias.
This is the real fear that drives the Kremlin to wage war against Ukraine and to support the Lukashenko dictatorship in Belarus, short of outright annexation (in the form of a Union of course) once Lukashenko's position becomes untenable.
The problem for Europe (and Poland in particular) is how to prevent that from happening and achieve a truly free Belarusian State.