The 2014 referendum wasn't 'won' or 'lost' by the SNP or any single political party.
The 'Yes' campaign was much broader than just the SNP, and included lots of other political voices/ strands.
It succeeded in getting a lot of people inspired/ interested in the future of the country, participating in political conversations and becoming more cynical about the mainstream media.
Unfortunately I believe the Scottish Govt has squandered a great deal of that energy and goodwill since.
They're very good at making policy pronouncements that sound great, but not at actually implementing things that work in practice.
Sure, Sturgeon did a better job than Johnson during the pandemic, but that was a pretty low bar.
The way they carried out gender recognition reform (and cases like 'Isla Bryson') -and introduced laughably bad 'hate crime'/ 'non-crime' legislation- alienated a lot of people. The Scottish Greens have totally lost their way/ any serious environmental focus/ credibility.
Working class communities have long seen Labour politicians taking the piss & mismanaging local councils, but have now seen that the SNP isn't any better, on an even bigger scale. (And there are still plenty of unanswered questions about Sturgeon, her husband and their camper van..)
And the Scottish Socialists never recovered from the saga of Tommy Sheridan. Alba has its problems. We're all fucked.