Difficulty bomb is fast approaching and the switching proposal from Proof-of-Work to Proof-of-Stake had been lay-out and ready to be launch soon maybe in a year and we have still time to mine before it is going to switch to PoS , i don't know what the future holds of ethereum mining. This difficulty chart
https://etherscan.io/chart/difficulty only tells the current difficulty of Ethereum but never tells a forecast of what the difficulty could happen in the next couple months. As a miner the reward and profitability of Ethereum mining are slimming each day and it may discourage us to mine which seems unsustainable and could lead to switch to mine another algo but that is the reality of mining profitability nothing really last long, being proactive is the only way to survive in mining.