After all possible Bitcoins are created, won't transaction fees eventually consume all Bitcoins?
There are two objections I would raise:

Miners have expenses. You need to pay your power bill. You need to pay your employees. You need to pay for new ASICs when the old ones inevitably become obsolete. You need to pay off your initial investment in ASICs. All of these things cost money.
You might object that miners wouldn't be doing this unless revenue exceeded expenses. This is true, but it's also true of every other profession. Therefore, we should view 'miners will eventually have all the money' the same way we view 'dentists will eventually have all the money.'

In general, people don't acquire money for the sake of having money. It's usually in service of some other kind of goal, like financial security, providing for someone else, or buying food. Sitting on a hoard of money that you cannot spend accomplishes none of these goals.