If you picked NextJS without knowing how it structures its middleware, the vendor lock-in to Vercel, its SSR strategy, its hydration schemes etc. that's on you. I, and many others, have had a lot of success with NextJS increasing delivery speed and ultimately, customer value.
Two years ago I moved off of the React ecosystem to Elixir/Phoenix/LiveView, and it's been great. But that's had its own challenges stemming from the design decisions its creators have made. You're always going to be running into things that you don't like, and I feel NextJS has just become an easy target for people who are looking to vent.