The devs will only agree to increase the blocksize when they will be confident that it won't harm the network. Maybe it will happen in a next few years, maybe in 5 years, maybe in 10, it's really hard to say.
It won't happen. Bitcoin isn't BCash where the far majority of the nodes are operated by just a few players licking each other's ass.
It's already near impossible to get the majority to upgrade to the most recent core versions, let alone have people line up to upgrade simultaneously. The risks by far aren't worth the 'gain' we would see kick in. Bitcoin has proven that users aiming for quality and security are willing to pay higher fees to obtain a spot in the next block.
On top of that, there isn't even a need to increase the blocksize with how we still aren't dealing with non stop full blocks. The backlog that forms during intensive day time usage hours is taken care of during the night. Fees are currently less than a penny. Even if the fees do a x100 it's still a dollar.
The main obstacle are the shitty clients not being able to properly calculate fees. They significantly inflate fees when the mempool fills up, which is unnecessary.