How can we avoid being screwed over in the future ? decentralized markets which are already in the works seem like the answer to me. As much as an individual vendor might still be able to exit scam the market as a whole would stay alive no matter what.
Are you talking about decentralized escrows or decentralized market architecture? Or both? They're distinct but as a user of the market the decentralization of escrow would be the only really noticeable of the two, and yes the future of markets immediately and for the medium term future will be decentralized escrow markets, maybe which will also have decentralized modular architecture as well which if done well would only be a plus.
Right now the following markets offer multi-sig escrows that are legit:
AlphaBay (whatever else may or may not be going on, I have zero attention to follow all this gossip crap, their multi-sig works for me, every time, I've not experienced any issue with my funds availability even in the few times I used regular central escrow, so AFAIC they're fine, but I would encourage using the multi-sig most/all of the time. The way it seems to be implemented, it would not be trivial for them to tamper with the multi-sig in a way that would allow them to steal money.)
Acropolis
Aflao
East India Company
Outlaw
Hansa
DarkRabbit
TheRealDeal
Valhalla
Tochka
Python
I can't vouch that every implementation is well-done completely or immune to manipulation, but each seems to be basically working as it should.
So in other words, that's basically every market except for like...Nucleus. And Dream.
You have to be walking around with your eyes closed chanting "see no evil" to avoid decentralized escrows these days or just be direct dealing, but centralized escrow is quickly losing prominence as an option, as well it should.
Personally I'd rather just handle my Bitcoins properly than potentially get my entire shit ripped off from an Admin who I had been pretty sure was a trustworthy dude for a while. Even if there was 0.5% chance for sure of the scam, I'd still say that's unacceptable if my entire holdings is potentially at stake.
Anyone who says otherwise, doesn't get how to use multi-sig probably because that's pretty damn crazy that you would rather take a dude who will rob you in the blink of an eye regardless if the shit hits the fan for him no matter what he said or how trustworthy he was before and even if he didn't even mean to eventually. Remove their ability to choose to rob you to the extent possible, and you no longer have to make character judgements or speculations about this or that, it's clear from the start.