Reminder you cannot buy skins without owning the champions, Riot is EXTREMELY unlikely to be doing some conspiracy to make champions harder to get for new players.

It just isn't one of riot's goals, they keep going more and more towards making champions easier to get not harder because it is no longer part of their core business model. You see more things like all champions unlocked via game pass than anything else.

Back in early seasons riot released a champion every month or something, it was not feasible to keep up with releases entirely via F2P and people buying champions was a significant part of their income. Skin shards, price reductions and so many events that give out shards/BE are designed to get as many champions as possible to be owned by people.

In like the last decade, there have been 3-4 releases a YEAR, trivial for established players to get them all. For newer players the unlock tracks are also generally far quicker to get champions than it is feasible to learn them.

IF, and this is BIG IF, riot made a change to make it significantly harder (silly 900 hours to get a champion numbers), it was not intentional as it makes no sense for anyone. Shifting it all into monthly passes which is better for 99.9% of new players and not the people who pick up the game for the first time and play 200 hours a week also counts as improving for new players.

No one, INCLUDING RIOT, wants to make getting champions harder, you can't buy the new elise skin you just saw on the trailer if you don't own elise. It just doesn't make any sense.

If I had to guess, the only reason all champions are not free already, is not to make any money on selling the champions, it's to add a sense of progression and not overwhelm new players.