As the original buyer of a physical game you are probably not going to get your moneys worth compared to playing on a sub unless you play that game for years and years, i'm sure we can agree that the number of games we fully get value out of compared to the amount we spent is going to be a small amount of games. If you buy many games, you cannot play every game for years so on average you will spend more on games than you would if you played on a sub for the same cost sunk.
However, when you think about the second hand market, one physical game that you buy new and then later sell is bought by someone else who then plays it and sells it on and on down the line. Only the money from that initial sale goes to the publisher. So, if a game ends up being played by 10 people the publisher could in theory have charged each of those people 1/10th of the money that the game cost new to subscribe to play it and still make the same amount of revenue. Each of those 10 consumers could have played the game for the same amount of time and effectively had a greater enjoyment/cost ratio whilst also giving the publisher the same revenue. In essence yes you are right, a sub service is setup to make the publisher more money but that doesn't mean that the customer has to equally lose that amount for it to pay off.
If anything the sub providers are stealing that revenue away from brick and mortar shops, Ebay, courier firms etc. rather than the consumer.