This thread reminded me that there was a fairly recent thread on this exact topic, and the bullet points I took away from that conversation was:
- abyssal runs are never designed to be guaranteed beatable (for any ship/fit plus room combo)
- each room “just is” and it’s up to players to figure out how to beat the room
- abyssals still follow the risk/reward tradeoff, particularly at higher tiers, which yes means ship losses happen – and since it can’t be eliminated, it’s up to the player to minimize them to maintain profitability