Bitcoin mining difficulty has been increasing and will continue to increase:


live chart here: https://www.coinwarz.com/mining/bitcoin/difficulty-chart

I don't see any reason why it would decrease. It's the best money ever invented, so it makes sense that more and more miners are interested in it over time.

You mentioned graphic cards, so I guess you're referring to mining alt coins. In that case this should be moved to the appropriate section of the forum.