The Big Bang Theory is still one of my favorite comedies around, and it's one of those that I consistently rewatch like Friends or Modern Family. What's great about it is that if you put on a random episode just to have something on, it works. Basically all of the characters had major milestones and character development - except for Raj.
In the "The Big Bang Theory: The Definitive Insider Story of the Epic Hit Series" book by Jessica Radloff, Raj actor Kunal Nayaar talked about his character's ending. As we saw over the course of 12 seasons, Raj eventually overcame his selective mutism, learned how to support himself without his wealthy father's money, and came to terms with self-love at the very end. Here's what the actor said in the book:
"I thought it was very astute that the one person who wanted love so badly realizes maybe he needs to love himself first. It doesn't have to come through someone else, and that's a very lovely way to end a character's storyline. He grew so much in those last few seasons as a character, and you saw him become less and less dependent on all the things he thought he needed, which is very beautiful."

Look, I do agree with Nayaar that Raj did go through some major milestones like his friends, and it was beautiful to see him come to terms with loving himself and not needing love to round him out. Though for someone who's such a helpless romantic, I still feel like Raj deserved to have a good love interest and even a grand, or at least meaningful, wedding just like everyone else. At some point. There was plenty of time to do it.
It didn't need to take 12 seasons for him to get to the place that he did. I am happy that he came to terms with his self-love eventually, because he's right. That is the first and most important step first before trying to be in a meaningful relationship. Though out of everyone, he was the one who deserved to find his soulmate the most, I'd argue. Everyone else's arcs, especially the most surprising one of Sheldon, were fleshed out over the seasons and they changed and learned for the better.

So I don't understand why Raj's was so behind compared to everyone else. We could have gotten this character development of the getting over the mutism, supporting himself, learning to self-love, then get to a nice storyline with someone he ends up with and falling in love. It can be hard to find characters that have chemistry with their onscreen partner, as well as the rest of the ensemble cast.
Though the characters of Bernadette and Amy joined in the later seasons, and it worked out wonderfully. The creative team could have found someone for Raj too. And that's still one thing rewatching The Big Bang Theory so many times that makes me question why it was so hard for the writers to do it. It's still one of my favorite shows. But even with you favorites, there's going to be something you didn't like, and Raj's ending is definitely one of them for me.
All 12 seasons of The Big Bang Theory are streaming on Max.