I think he is still in the early ages, where cavalry is god and there is not many things that could counter it.
Let me see, if you have 7 HC, 5 raiders and 1 supply it means that your limit is 65. This means that you are classical age if I am not wrong.
Evertything is easier there, no goog base deisgns most of the times and even the good ones does not have the DPS needed to kill your army, 1 Balista at best and weak towers, Go to Gunpowder and Enlightment age and check theie layouts walls etc. When you must get through a well designed base with at least 6 walls (if the AI god is with you, most of the time it is not) each with 12 000 HP (Level 7) at least then we will talk. I am actually pretty sure that most of the bases can't be killed by cavalry even if the towers and the defenders are doing 0 DMG to you.
The other issue with the cavalry is that foot soldiers are masacred by Mortars and Redoubts, the cannons are frequently attacked by cavalry defenders as there are 3 stables each spawning 3 lancers per wave. So things gets quite complicated with late ages and good base designs. Even if you are winning you will not have enough time to kill the defences which means that you've just lost your entire army. You will not have enough DPS to punch through the defender waves, general and towers.
Add to all that the improved AI which everyone hates, though it is the best upgrade ever, it adds personality to your units. They get special perks like complete rage against wall, attacking every piece of it. As an addon bonus they also get claustrofobia now, narrow spaces are not for them, they prefer to take a long walk and kick the crap out of that wall on the other side.