The fact that you have to be at a shop to buy items makes it so you have to think carefully about when you want to leave your position to shop without losing a big objective. It also makes it so people can’t snowball heavily in the lane since they could either stay in the lane after killing the enemy carry and try to keep pushing with decent items or go to a shop and buy better items so they won’t get destroyed the next lane matchup.
As for the touch controls complaint, the touch controls are much easier on the fingers since you don’t need to continuously have your left thumb being used to move around. The touch controls are much more intuitive since you get to decide specifically what you want to attack instead of being forced to prioritize whatever is in your range and end up missing an important basic attack due to it. There’s also the fact that many heroes cannot be played with joystick controls assuming the same ability layout is used due to them having a really tiny AoE or requires fast tapping of enemies/locations such as Ozo’s acrobounce.
Another concern with joystick controls is the fact that there are active items you can buy in the shop of Vainglory. These items either run down the side of your screen if you are on mobile or on the bottom if you are on a tablet. If a joystick were to be added, it would be interfering with the space needed for the items. Even if they do have some space, you will end up being forced to stand still to end up using your items since you wouldn’t be able to move while tapping on the items.
Trust me, you will get used to it. Given the depth and complexity of Vainglory, which is dedicated to giving a true PC MOBA experience, the touch controls we have now are necessary.