Agree wholeheartedly, but purely from a gameplay standpoint. I'm a longtime Clash Royale player and this same monetization model has been an unending source of frustration.
Card leveling progression necessarily creates bad matches as the average experience. The only way to create balance in a system with uneven player deck strengths is to factor that into the matchmaking, using a player's success as their matchmaking score; e.g. a good player with a medium strength deck will be matched against an average player with a high strength deck. This quite nicely creates 50/50 win loss ratios, which seems like good matchmaking. The problem is that it's not fun. It's not fun to play against less skilled players who have a strength advantage; the strategy will be lacking (a bad quality in a strategy game) and the match will just be going through well tread motions of grinding against uneven odds. Repeat this process ad infinitum until you reach max deck strength, a process always balanced to take years. Only after this ridiculous investment can you start reliably being matched into matches based on skill.
And that's not even mentioning the long term investment problem. CnC Rivals will naturally add units over time, which will start at base level. So, when you're maxed at whatever level and then Chemical Tanks are added in six months, you'll have a fun new unit that's completely useless to you because it'll be ten levels below the rest of your deck and will continue to be useless until you can collect enough cards to reach near parity.
As stated by OP, the Chest box model is undeniably profitable and there's likely no changing the business decisions that went into it being decided for this game in the first place. However, there's also no denying that it negatively impacts gameplay purely for the purpose of monetization and Command and Conquer Rivals will be a better game without it.
