Not really sour grapes btw, without going into depth that would giveaway the employer, the 3 devsnthat I worked with had been unable to implement functionality that had been invented within the last 5-10 years because they never did their own research or keep up with trends. As an analogy think akin to them only ever using traditional SQL DBs, then being shown a massive serverless distributed db that didn't use SQL, that required software redesign for eventual consistency, couldn't do ACID transactions, all needed for a small high value, short deadline project, and you get some idea of the scope of change and steep learning curve they struggled to address. I'll restate this is not the actual problem, but the scope and impact is of the same size.
If that's sour grapes by your definition then ok :), but for me for BE devs around my own age, it seems a little underwhelming.