I’ve read the book five times (once in Italian!) and I would just point out that we have to be careful about judging endings from our own timeframe and cultural vantage point. It’s good to know something about the Neoclassical period and the structure of its art. For me, P&P is a tapestry of characters that weave among one another much as in the dances of the day. It’s not so much about the ending as how the characters lives are resolved through Austen’s craft, where no loose ends are left.
It is, in fact, an exercise in style.