High fees will be the downfall to mainstream adoption?

[Macadonian]

The high fees currently are preventing general users sending their Bitcoin, but is also causing a lot of the exchanges to charge an absurd amount to process the order and cover the mining fee.

I think this is going to be one of the biggest milestones in achieving mainstream adoption. The fees are starting to climb down a little now. But what is stopping this from happening every so often and costing businesses which deal in Bitcoin a huge amount of money to trade in it?

What is the answer to correcting this issue that we've encountered the last few weeks? As it stands there's 100k unconfirmed transactions in the mempool.