In theory the release clause benefits only the player, as the club cannot refuse an offer matching the clause.
In practice, however, a very high release clause is used by the clubs to their advantage. Firstly, it deters other clubs from pursuing the player. Secondly, it is used in negotiations, where the club says to the player and the potential buyer: "look, this is the price that we agreed with the player and there is no way he could move for any less". And since the player has already accepted the valuation set in his release clause, the pressure is on the buyer to match it, and not on the seller to lower it.
The only question is if 150 mln is not a tad too low in today's market. On the other hand, if Dybala is worth 150 mln, we will have to renegotiate his contract anyway.