It should be hard to 5* tough opponents. It should be easy and cheap to do easy opponents. Right now, the old easy ones are suddenly still doable but at high cost in retrain time and tactics, and the hard ones are near impossible and ridiculously expensive in the form of complete army rebuilds. But that is just my opinion on how it should be - people can and do differ.
The key is that the game needs to be fun - enough for most current players to keep playing, and new ones to keep joining and moving up. If it is, then it will survive and do fine, whether or not I still find it fun.
My opinion is that the recent changes are making the game much less fun. If the people on this forum saying similar things are outliers, this will all be fine. If not, and especially if it is worst for the lower level players, the game is in trouble.
Those who I see happy on here seem to be those who have top level bases and / or were already big heavy tank users. My CWA with maxed HTs is doing fine - it is pretty boring to play anyway, because upgrades take forever and walls are done, so there isn't much to do. And war is not that fun, so opted out. My other accounts are a bit obnoxious to try to do multiple attacks in a row now, but I am letting them die slowly - play a battle or two when I feel like it, otherwise ignoring them. I would guess people who are in that boat with only one account are about ready to quit entirely.