Why do we even need to buy champs

It's kinda bogus that we still have to buy champs in order to play them off of free week. Games like Overwatch and Dota let you access all heroes free of charge, so why doesn't League? It takes away from the value of the game because you have limited options.

Not only this, but the prices to buy champs are absolutely outrageous, and with this new system of BE, it's gonna take even longer to grind for them.

Not ONLY this, but when you play champions on free week, you can't get loot rewards because you don't own them, which basically sets you back even more and wastes a game of possible loot.

I get that it does effectively raise game quality because people take time to learn champions before they buy them and can play them in Ranked. How about instead, every account owns every champ. But, in order to play the champ in Ranked, you need to be something like Mastery 3 with them, or have gotten an S with them, to show that you at least have a slight idea of what you're doing.

I've been playing League for about 3 years now and I still don't own 47 champs, some of which I'm Mastery 3 with and have gotten high scores on before. This has always been my biggest gripe about the game.

Can we address this?