Gears of War 4 - Matchmaking

For the Competitive I'd say yes, not many people play those modes. However that may have/will change with the new update providing players Escalation Beta to get a feel for what I consider a very fun mode. For the Core I don't think it is lack of players,
though have you tried to play at different times of the day/night? Also, try and get a party going and have more players for a lobby. Gears 4 is far from being right when it comes to matchmaking, but it has gotten better (though that's really not saying much).
Good luck.

Por el modo de juego que mencionas (escalada) asumo que juegas Gears of War 4. En este caso el desarrollador del juego eliminó del juego hace un tiempo la opción de seleccionar un servidor (como era posible en Gears Of War Ultimate) y ahora en su lugar hará
el matchmaking con usuarios cercanos a ti.

English: For the game mode he mentions (escalation), I assume that you're playing Gears of War 4. In this case, the game's developer deleted the option of choosing a server to play in (as it was on GoW Ultimate) and now the matchmaking will place you with
gamers within your region.

I'm fairly sure that Gears of War 1 has that feature, but in all honesty I think most use matchmaking.

el juegoes Gears of war 4

(Mod Translation)

The games Gears of War 4

Gears of War, Gears of War 2, and maybe Forza 4.