The company I work at has fully embraced vibe coding, so from my experience: it did seem faster at first, but also the amount of regressions and new bugs being introduced has gone up dramatically, and so the overall workflow has stabilised to be roughly just as fast as before AI, but now almost all mental energy is going into QA and reviewing. From the customer perspective, they saw lots of new progress initially, but have now been frustrated by constantly finding things broken or buggy.

And all this is at a company which has entire teams dedicated to trying to improve AI-based workflows and tools to make them more reliable.

So no. From someone in the field, quality has dropped a lot, and speed is only increased if you close your eyes and ignore all the tech-debt being created.