As far as I can tell, matchmaking does not work like it used to in previous titles.
Instead of having persistent servers that you can join, servers are rolled after every game. This means that you and the people you were playing with get rematched to another server at the end of a round.
Since you can filter your matchmaking experience, and most players are probably already in a game or not searching at the time you are, the available pool of matches is small unless the region you are searching in is especially large or the time is very popular.
Another factor might be the way servers are managed in a cloud-based architecture, where potentially too many servers are spun up in response to perceived player demand, spreading the available pool across too wide a base.
There is also a major filter with crossplay, if you don't enable that, and if you do, how heavily the matchmaking weighs assigning you to similar platforms. Some regions may have more or less players on a certain platform, making it more or less an issue.
The obvious solution is server persistence. The problem is how does the matchmaker select the next mode/map with all the preferences of each player baked in? Its not possible, and if you don't try, people could leave, causing the server to empty out or become unbalanced.
The search times are already quite long, I don't think making them longer improves the experience. You're trading one evil for another. People will just bail out of the matchmaking queue.
Bots not counting towards K/D pretty much destroyed the value of populating servers with bots, and it is pretty clear the community don't like bots in their servers anyway, but don't like empty servers or long wait times either.
So it is a non-trivial problem. The best solution I can think of is to try improve the server management and player merging across servers, or introduce some kind of compromise on managing player search preferences to reduce the likelihood of players leaving.
