There are some ways of doing f2p right. Dota 2 is a good example. In dota 2, you start with all the content unlocked. You can play any hero you want for free. There are no features that affect gameplay that can be bought.

The only thing you can pay for is cosmetic effects. You can buy new costumes for your characters. You can pay for announcer packs. You can get new animations and make the team's courier look like cute animals.

That's how f2p should be done. Unfortunately, most games don't do it like that. They hide characters behind a pay wall. They let you become more powerful by spending in game currency, then let you buy that currency with real money. That system is broken.

The only good f2p is cosmetics only.