Why is the shop for hero upgrades (e.g. additional attack power) outside of the gameplay?

What I mean is, in traditional MOBAs, the point is to kill minions / enemy heroes to gather money, then return to the shop to buy new items before returning to the lane.

By putting the shop outside of the gameplay, in a special upgrade screen, it will make the game unbalanced because e.g. a level 6 player will have a much stronger champion to begin with!

The shop has to be inside the game with access during a round, so that all players start the round equally strong and get stronger throughout the round!

Awesomenauts did the same mistake in the beginning, letting players choose their loadout before the round started. By now, they have also moved the shop completely in-game.

This has to be done!