Hello Cruelgreen, I read your concern about block and i can assure you those concerns are redundant. PP stalling is a strategy that can be used to break pokemons that don't have a way to deal with constant healing from a tanky pokemon and it is not any worst than people using pokemons with regenerator ability and switching between enemy atacks and using pokemons with a reliabe healing move and constantly spam healing to wear down opponents pp.
Lets talk about slowbro with recycle and leppa berry; This slowbro set sounds good on theory, if you catch an opponent pokemon and block them, if they have no way of dealing more than 50 percent damage to slowbro, you can wear down their pp. In pokemon pvp system swtiching out a pokemon always has maximum priority so opponent has their chance to switch out unlike (arena trap ability which was used to trap and revenge kill pokemons and give people no chance thats why it was banned.) , lets say opponent switch out to an electric type or a dark type that can deal huge damage to slowbro or they switch out to a pokemon with the move Taunt or they switch to a pokemon that can use setup moves and dont mind being trap against a slowbro that cannot deal any damage to them and opposes zero threat, these were the good scenarios for the opponent now lets talk about bad scenarios, opponent switches to a pokemon that cannot deal with slowbro and they get blocked if this happens they lose that pokemon,they wont lose the whole match, its a bad play on their part. when someone first encounters a pokemon set like this and they lost to it they will not forget and they are expected to not to repeat their mistake next time.The point is this slowbro move set has its counters and not hard to handle unless the opponent is using a similiar strategy themselves. When games reach to maximum turns they end on a draw even. maybe you have lost time but you will not be defeated. If this strategy was succesfull everybody would use it and it would get banned accordingly, and people can play however they like aslong as they are not cheating, this wont make them a ''poor sportsman''. there is no reason to ban a move like block from pvp without testing it. Block has never been banned in any smogon meta game and this shows those type of strategies arent as succesfull.
If you read this, thank you. I hate writing , This took me 40 minutes, hope you enjoyed reading it. Take care.