I don't know if anyone else really holds this belief, but I feel that the Empires fall was a bit too quick personally speaking based on the current Expanded Universe's lore. Originally the conflict lasted for another 15 years after Darth Vader & Palpatine were killed on the second Death Star in 4 ABY.

While the Rebel Alliance (Now the New Republic) continued to capture important worlds such as Naboo, Sullust, Kashykk, & Coruscant, but they still knew they were outnumbered due to how large the Imperial army & Navy were. So they basically just sat back and watched as the remnants of the Empire led by high ranking officials (now Warlords) killed each other over what they should control due to the power vacuum left behind, while the nominal Imperial Government couldn't really do anything to stop the infighting. I mean two imperial Grand Admiral’s literally killed each other over who should control the correlian sector.

When the time was right, The New Republic did more devastating campaigns against the Imperial Warlords and remnants causing them even more devastating losses & damage, until Grand Admiral Thrawn came back and reunified the remaining imperial world’s & military under his command where they then actually made scarily good progress against the New Republic, nearly destroying them until he was assassinated. After that the war continued until The Bastion Accords were signed which basically formed the Imperial remnant as a legitimate state afterwards, and then there was peace and cooperation between The New Republic and Imperial Remnant. This seemed quite realistic and believable to me as someone who's a huge history nerd who's studies real-world Empire's and other states or kingdoms that had similar fates.

Whereas in the modern canon they claimed that the Empire falls only a YEAR after Endor, that feels way too quick & unrealistic personally speaking when we look at real world empires throughout history, I mean The Romans and Achmided Persians for instance took hundreds of years until they finally fell. But even then some don't see it as the Achmided Empire falling rather that it "changed hands of power" while Rome also technically didn't fall until the 1400s. So for the galactic empire to fall this quickly it just seems unbelievable even if Gallius Rax was self sabotaging things for the imperial remnants.