You are correct that queueing for MSQ content can take hours. This is a huge problem in the game that hurts new players, but SE can't do much more than they already do to help the situation. Playing during the morning NA/EU time makes this worse.
Deltascape normal is served by Normal Raid roulette, Mentor Roulette and people queueing directly. I think that it shouldn't take too long to get into these, but if it does I suggest joining an FC or recruiting in Party Finder.
Deltascape savage is not normally done by queueing directly on NA datacenters, but by joining a static, recruiting in Party Finder or joining a discord (a lot of people have small raiding discords that you end up in when you're pugging them).
I notice your world is set as Tonberry, which is a JP world. On JP DC I am told they make better use of queueing directly for savage raids. Of course, you'll struggle if you don't tick the box to be paired with the language the majority of the DC uses.
Important to remember is that Deltascape is not a current raid and that people usually focus on the most recent raid. The most current raid is Alphascape. Its raiding tier would normally be over by now, but a new one won't replace it for about 2 months, so there is an activity lull until then which may contribute to making it harder to find people.
You do need to complete Deltascape normal to progress to Sigmascape and Alphascape normal. You do not need to complete Deltascape savage to progress to Sigmascape and Alphascape savage.
