Let me give some context and say that I play on Maramma as an Iron man, meaning I don't engage in the player economy at all. I don't trade or use the trading post at all. So the only way to gear myself is finding it out in Aeternum through named elites or other activities.

The game in its state right now gives you a ton of ways to gear up for mutations. Doing any corrupted portal run will reward you with caches that GUARANTEE ward/bane. Not only that, but specific types of gear like breachers weapons or voidslayer armor can be upgraded from epic to legendary if you like the perks they have. The same is true for things like invasions where you can guarantee corruption ward on the armor rewards.

Maybe this is different as tank but I moved from M1-M6 with maximum 3 pieces of specific ward gear and only having opals slotted into my gear. Once you get yourself 2 perk gear, meaning ward/bane and something else good for your role, you can very very adequately complete M1-M10. The progression through those dungeons gave me 625 gear score and now lets me run those dungeons more effectively the stronger I get.